Chapter 23: Cognitive Development in Early Adulthood

Chapter 23 Learning Objectives

  • Distinguish between formal and post formal thought
  • Describe dialectical thought
  • Describe the changes in educational attainment and the costs of education
  • Describe the benefits of education beyond high school
  • Describe the stages in career development, millennial employment, and NEETS
  • Describe sexism and how it affects pay, hiring, employment, and education

Beyond Formal Operational Thought: Postformal Thought 

As mentioned in chapter 6, according to Piaget’s theory adolescents acquire formal operational thought. The hallmark of this type of thinking is the ability to think abstractly or to consider possibilities and ideas about circumstances never directly experienced. Thinking abstractly is only one characteristic of adult thought, however. If you compare a 15-year-old with someone in their late 30s, you would probably find that the latter considers not only what is possible, but also what is likely. Why the change? The adult has gained experience and understands why possibilities do not always become realities. They learn to base decisions on what is realistic and practical, not idealistic and can make adaptive choices. Adults are also not as influenced by what others think.  This advanced type of thinking is referred to as Postformal Thought (Sinnott, 1998).


Dialectical Thought: In addition to moving toward more practical considerations, thinking in early adulthood may also become more flexible and balanced. Abstract ideas that the adolescent believes in firmly may become standards by which the adult evaluates reality. Adolescents tend to think in dichotomies; ideas are true or false; good or bad, and there is no middle ground. However, with experience, the adult comes to recognize that there are some right and some wrong in each position, some good or some bad in policy or approach, some truth and some falsity in a particular idea. This ability to bring together salient aspects of two opposing viewpoints or positions is referred to as dialectical thought and is considered one of the most advanced aspects of postformal thinking (Basseches, 1984). Such thinking is more realistic because very few positions, ideas, situations, or people are completely right or wrong. So, for example, parents who were considered angels or devils by the adolescent eventually become just people with strengths and weaknesses, endearing qualities, and faults to the adult.

Does everyone reach post formal or even formal operational thought? Formal operational thought involves being able to think abstractly; however, this ability does not apply to all situations or all adults. Formal operational thought is influenced by experience and education. Some adults lead lives in which they are not challenged to think abstractly about their world. Many adults do not receive any formal education and are not taught to think abstractly about situations they have never experienced. Further, they are also not exposed to conceptual tools used to formally analyze hypothetical situations. Those who do think abstractly may be able to do so more easily in some subjects than others. For example, psychology majors may be able to think abstractly about psychology but be unable to use abstract reasoning in physics or chemistry. Abstract reasoning in a particular field requires a knowledge base we might not have in all areas. Consequently, our ability to think abstractly often depends on our experiences.


According to the National Center for Higher Education Management Systems (NCHEMS) (2016a, 2016b, 2016c, 2016d), in the United States:

  • 84% of 18 to 24-year-olds and 88% of those 25 and older have a high school diploma or its equivalent
  • 36% of 18 to 24-year-olds and 7% of 25 to 49-year-olds attend college
  • 59% of those 25 and older have completed some college
  • 32.5% of those 25 and older have a bachelor’s degree or higher, with slightly more women (33%) than men (32%) holding a college degree (Ryan & Bauman, 2016).

The rate of college attainment has grown more slowly in the United States than in a number of other nations in recent years (OCED, 2014). This may be due to the fact that the cost of attaining a degree is higher in the U.S. than in many other nations.

In 2017, 65% of college seniors who graduated from private and public nonprofit colleges had student loan debt, and nationally owed an average of $28,650, a 1% decline from 2016 (The Institute for College Access & Success (TICAS), 2018). See Figure 7.17 for yearly comparisons.

Figure 7.17

According to the most recent TICAS annual report, the rate of debt varied widely across states, as well as between colleges. The after graduation debt ranged from 18,850 in Utah to $38,500 in Connecticut. Low-debt states are mainly in the West and high-debt states in the Northeast. In recent years there has been a concern about students carrying more debt and being more likely to default when attending for-profit institutions. In 2016, students at for-profit schools borrowed an average of $39,900, which was 41% higher than students at non-profit schools that year. In addition, 30% of students attending for-profit colleges default on their federal student loans. In contrast, the default level of those who attended public institutions is only 4% (TICAS, 2018).

College student debt has become a key issue at both the state and federal political level, and some states have been taking steps to increase spending and grants to help students with the cost of college. However, 15% of the Class of 2017’s college debt was owed to private lenders (TICAS, 2018). Such debt has less consumer protection, fewer options for repayment, and is typically negotiated at a higher interest rate. See Table 7.1 for a debt comparison of 6 U.S. States.

Table 7.1

Graduate School: Larger amounts of student debt actually occur at the graduate level (Kreighbaum, 2019). In 2019, the highest average debts were concentrated in the medical fields. Average median debt for graduate programs including:

  • $42,335 for a master’s degree
  • $95,715 for a doctoral degree
  • $141,000 for a professional degree

Worldwide, over 80% of college-educated adults are employed, compared with just over 70% of those with a high school or equivalent diploma, and only 60% of those with no high school diploma (OECD, 2015). Those with a college degree will earn more over the course of their lifetime. Moreover, the benefits of a college education go beyond employment and finances. The OECD found that around the world, adults with higher educational attainment were more likely to volunteer, felt they had more control over their lives, and thus were more interested in the world around them. Studies of U.S. college students find that they gain a more distinct identity and become more socially competent, less dogmatic and ethnocentric compared to those not in college (Pascarella, 2006).

Is college worth the time and investment? College is certainly a substantial investment each year, with the financial burden falling on students and their families in the U.S., and mainly by the government in many other nations. Nonetheless, the benefits both to the individual and society outweigh the initial costs. As can be seen in Figure 7.18, those in America with the most advanced degrees earn the highest income and have the lowest unemployment.

Figure 7.18

Career Development and Employment 

Work plays a significant role in the lives of people, and emerging and early adulthood is the time when most of us make choices that will establish our careers. Career development has a number of stages:

Stage One: As children, we may select careers based on what appears glamorous or exciting to us (Patton & McMahon, 1999). There is little regard in this stage for whether we are suited for our occupational choices.

Stage Two: In the second stage, teens include their abilities and limitations, in addition to the glamour of the occupation when narrowing their choices.

Stage Three: Older teens and emerging adults narrow their choices further and begin to weigh more objectively the requirements, rewards, and downsides to careers, along with comparing possible careers with their own interests, values, and future goals (Patton & McMahon, 1999). However, some young people in this stage “fall-into” careers simply because these were what was available at the time, because of family pressures to pursue particular paths, or because these were high paying jobs, rather than from an intrinsic interest in that career path (Patton & McMahon, 1999).

Stage Four: Super (1980) suggests that by our mid to late thirties, many adults settle in their careers. Even though they might change companies or move up in their position, there is a sense of continuity and forward motion in their career. However, some people at this point in their working life may feel trapped, especially if there is little opportunity for advancement in a more dead-end job.

How have things changed for Millennials compared with previous generations of early adults? In recent years, young adults are more likely to find themselves job-hopping, and periodically returning to school for further education and retraining than in prior generations. However, researchers find that occupational interests remain fairly stable.  Thus, despite the more frequent change in jobs, most people are generally seeking jobs with similar interests rather than entirely new careers (Rottinghaus, Coon, Gaffey & Zytowski, 2007). As of 2016, millennials became the largest generation in the labor force (Fry, 2018) (See Figure 7.19).

Figure 7.19

NEETs: Around the world, teens and young adults were some of the hardest hit by the economic downturn in recent years (Desilver, 2016). Consequently, a number of young people have become NEETs, neither employed nor in education or training. While the number of young people who are NEETs has declined more recently, there is concern that “without assistance, economically inactive young people won’t gain critical job skills and will never fully integrate into the wider economy or achieve their full earning potential” (Desilver, 2016, para. 3). In parts of the world where the rates of NEETs are persistently high, there is also concern that having such large numbers of young adults with little opportunity may increase the chances of social unrest.

In the United States, in 2017 over 13% of 15 to 29 year-olds were neither employed nor in school, (Organisation for Economic Cooperation and Development, (OECD), 2019). This is down from 2013 when approximately 18.5% of this age group fit the category (Desilver, 2016). More young women than men in the United States find themselves unemployed and not in school or training for a job. Additionally, most NEETs have a high school or less education, and Asians are less likely to be NEETs than any other ethnic group in the US (Desilver, 2016).

The rate of NEETs varies around the world, with higher rates found in nations that have been the hardest hit by economic recessions, and government austerity measures. The number of NEETs also varies widely between the genders, although females are more likely to be NEETs in all nations (see Table 7.2).

Table 7.2

What role does gender play in career and employment? Gender also has an impact on career choices. Despite the rise in the number of women who work outside of the home, there are some career fields that are still pursued more by men than women. Jobs held by women still tend to cluster in the service sector, such as education, nursing, and child-care worker. While in more technical and scientific careers, women are greatly outnumbered by men. Jobs that have been traditionally held by women tend to have lower status, pay, benefits, and job security (Bosson, et al., 2019). In recent years, women have made inroads into fields once dominated by males, and today women are almost as likely as men to become medical doctors or lawyers. Despite these changes, women are more likely to have lower-status, and thus less pay than men in these professions. For instance, women are more likely to be a family practice doctor than a surgeon or are less likely to make partner in a law firm (Ceci & Williams, 2007).


Sexism or gender discrimination is prejudice or discrimination based on a person’s sex or gender (Bosson, Vandello, & Buckner, 2019). Sexism can affect any sex that is marginalized or oppressed in society; however, it is particularly documented as affecting females. It has been linked to stereotypes and gender roles and includes the belief that males are intrinsically superior to other sexes and genders. Extreme sexism may foster sexual harassment, rape, and other forms of sexual violence.

Sexism can exist on a societal level, such as in hiring, employment opportunities, and education. In the United States, women are less likely to be hired or promoted in male-dominated professions, such as engineering, aviation, and construction (Blau, Ferber, & Winkler, 2010; Ceci & Williams, 2011). In many areas of the world, young girls are not given the same access to nutrition, healthcare, and education as boys. Sexism also includes people’s expectations of how members of a gender group should behave. For example, women are expected to be friendly, passive, and nurturing; when a woman behaves in an unfriendly or assertive manner, she may be disliked or perceived as aggressive because she has violated a gender role (Rudman, 1998). In contrast, a man behaving in a similarly unfriendly or assertive way might be perceived as strong or even gain respect in some circumstances.

Occupational sexism involves discriminatory practices, statements, or actions, based on a person’s sex, that occur in the workplace. One form of occupational sexism is wage discrimination. In 2008, the Organisation for Economic Co-operation and Development (OECD) found that while female employment rates have expanded, and gender employment and wage gaps have narrowed nearly everywhere, on average women still have a 20 percent less chance to have a job. The Council of Economic Advisors (2015) found that despite women holding 49.3% of the jobs, they are paid only 78 cents for every $1.00 a man earns. It also found that despite the fact that many countries, including the U.S., have established anti-discrimination laws, these laws are difficult to enforce. A recent example of significant wage inequality occurred among athletes.

2019 Women’s World Cup: The world witnessed the tremendous athleticism and soccer skills demonstrated by female players from 24 different countries during the 2019 Women’s World Cup. Amid the cheering at the end of the final match between the United States and the Netherlands, were chants of “equal pay” (Channick, 2019).  Throughout the tournament, attention was focused on the discrepancy between what male soccer players earned compared to the female players. In winning the World Cup, the American women’s team earned $4 million as part of a $30 million prize pool (Peterson, 2019). In contrast, the French men’s team, who won the Men’s World Cup in 2018, earned $38 million as part of the $400 million prize pool. The Federation of Association Football (FIFA) promised to double the prize money to $60 million for the 2023 Women’s World Cup, but that still lags far behind the $440 million that will be given out for the Men’s World Cup in 2022. In the United States, the women’s soccer team generates more revenue and receives higher TV ratings than the men’s team, yet the women get paid significantly less. By winning the 2019 Women’s World Cup, each woman should receive $200,000, yet if the American men had won the 2018 Men’s World Cup, each would have received $1.1 million (Hess, 2019). Because of this discrepancy, in March 2019, 28 members of the women’s team filed a lawsuit against the United States Soccer Federation for gender discrimination and unequal pay (Channick, 2019).

Factors Affecting Wage Inequality: There are many possible explanations for the wage gap. It has been argued in the past that education may account for the wage gap. However, the wage gap exists at every education level (Bosson et al., 2019). Men with less than high school to men with graduate degrees earn more than women with the same level of education. In addition, women now attain more associates, bachelor’s, and master’s degrees than men, and very similar levels of professional degrees and doctorates, according to a recent Census survey (U.S. Census Bureau, 2019). As the wage gap still exists in most occupations it cannot be the explanation. Instead, occupational segregation is a likely contributor to the overall wage gap, as women tend to work in very different occupations than men, and those jobs tend to have lower wages. In addition, the entry of women into a field tends to reduce the wages and prestige of the job. Mandel (2013) found that jobs typically held by men who saw the biggest influx of women into those careers also saw the biggest drop in wages.

Sticky floors, which keep low-wage workers, who are more likely to be women and minorities, from being promoted contribute to lower wages (Bosson, et al. 2019). Women are disproportionately in low-paid occupations, such as clerical, childcare, and service workers (Hegewisch & Ellis, 2015). They also get paid less than men in the same jobs, as can be seen in Table 7.3 women paid more than men on average; stock clerk. Men are not only being paid more in more masculine jobs but also in jobs typically held by women.

Table 7.3

Other factors include that more than half of men report having negotiated their salary when being hired, compared with 12% of women (Babcock, Gelfand, Small, & Stayn, 2006). However, people perceive women who negotiate more negatively then they do men, as assertive women, but not men, are more likely to be penalized. Women are also more likely to have interruptions in their careers either through the birth of children, or relocation due to a change in their partner’s job. Women are also less likely to relocate for the sake of their families when a better job offer comes along, and employers know this. It has been suggested that one reason why males may be offered more money is to keep them from leaving (Baldridge, Eddleston, & Vega, 2006). Additionally, men are more likely to work overtime.

Barriers to Positions of Power: There are a few barriers to women achieving positions of power. The glass ceiling is the invisible barrier that keeps women and minorities from rising to higher positions regardless of their qualifications (Bosson et al., 2019). Women hold only 4.5% of CEO positions and 14% of top executive positions around the world (Noland, Moran, & Kotschwar, 2016). In addition, Noland and colleagues found that in a study of nearly 22,000 companies worldwide, in 77% of those firms only 30% of women held an executive position or board seat. There were only 11 companies, or 0.05% of all the firms studied, where women held all the executive positions and board seats. Some researchers see the root cause of this situation in the tacit discrimination based on gender, conducted by current top executives and corporate directors, who are primarily male.

Often the barriers to achieving one’s goals are not obvious. For instance, some argue that the gender role stereotypes cast managerial positions as “masculine”. Unfortunately, when women do rise to positions of power it is often at a time when a company or country is faced with a major crisis. This is called the glass cliff, and it refers to women and minorities being placed in leadership positions when the risk of failure is high. For instance, female lawyers are more likely than their male counterparts to lead high-risk cases, and female politicians are more likely to be recommended to run in unwinnable seats (Bruckmuller, Ryan, Floor, & Haslam, 2014).

Worldwide Gender Parity: The World Economic Forum (2017) introduced The Global Gender Gap Report in 2006 as a way of tracking gender-based disparities between men and women in the world. The most recent report in 2017 analyzed 144 countries on gender equality in the areas of economic participation and opportunity, educational attainment, health and survival, and political empowerment. Countries are then ranked to create global awareness of the challenges posed by gender gaps in different areas of the world. A parity rating of 100% would mean that females and males achieved equality on these measures. Results indicated:

  • 68% of gender parity was found worldwide across the four areas. Specifically, there was 96% parity in health outcomes, 95% parity in educational attainment, 58% parity in economic participation, and only 23% parity in political empowerment.
  • The top spots were held by smaller Western European countries, particularly the Nordic countries as Iceland (88% parity), Norway (83% parity) and Finland (82% parity) occupied the top three positions.
  • The United States ranked 49th with 72% gender parity.
  • Following the current trends, it will take 100 years for global gender parity.
  • Improving gender parity is expected to provide significant economic gains for a country and closing the occupational gender gaps would be one way to achieve this.


Allendorf, K. (2013). Schemas of marital change: From arranged marriages to eloping for love. Journal of Marriage and Family, 75, 453-469.

Alterovitz, S., & Mendelsohn, G. A. (2011). Partner preferences across the life span: Online dating by older adults. Psychology of Popular Media Culture, 1(S), 89-95.

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (Fifth Edition). Washington, D. C.: Author.

American Psychological Association. (2016). Sexual orientation and homosexuality. Retrieved from

Arnett, J. J. (2000). Emerging adulthood: A theory of development from late teens through the twenties. American Psychologist, 55, 469-480.

Arnett, J. J. (2001). Conceptions of the transitions to adulthood: Perspectives from adolescence to midlife. Journal of Adult Development, 8, 133-143.

Arnett, J. J. (2003). Conceptions of the transition to adulthood among emerging adults in American ethnic groups. New Directions for Child and Adolescent Development, 100, 63–75.

Arnett, J. J. (2004). Conceptions of the transition to adulthood among emerging adults in American ethnic groups. In J. J. Arnett & N. Galambos (Eds.), Cultural conceptions of the transition to adulthood: New directions in child and adolescent development. San Francisco: Jossey-Bass.

Arnett, J. J. (2006). G. Stanley Hall’s adolescence: Brilliance and non-sense. History of Psychology, 9, 186-197. Arnett, J.J. (2007). The long and leisurely route: Coming of age in Europe today. Current History, 106, 130-136.

Arnett, J. J. (2011). Emerging adulthood(s): The cultural psychology of a new life stage. In L.A. Jensen (Ed.), Bridging cultural and developmental psychology: New syntheses in theory, research, and policy (pp. 255–275). New York, NY: Oxford University Press.

Arnett, J. J. (2016). Does emerging adulthood theory apply across social classes? National data on a persistent question. Emerging Adulthood, 4(4), 227-235.

Arnett, J. J., & Taber, S. (1994). Adolescence terminable and interminable: When does adolescence end? Journal of Youth and Adolescence, 23, 517–537.

Aquilino, W. S. (2006). Family relationships and support systems in emerging adulthood. In J. J. Arnett & J. L. Tanner (Eds.), Emerging adults in America: Coming of age in the 21st century (pp. 193-217). Washington, DC: American Psychological Association.

Babcock, L., Gelfand, M., Small, D., & Stayn, H. (2006). Gender differences in the propensity to initiate negotiations. In D. De Cremer, M. Zelenberg, & J.K. Muringham (Eds.), Social psychology and economics (pp. 239-262). Mahwah, NJ: Lawrence Erlbaum.

Back, M. D., Schmukle, S. C., & Egloff, B. (2008). Becoming friends by chance. Psychological Science, 19(5), 439–440. Bailey, J. M., & Pillard, R. C. (1991). A genetic study of male sexual orientation. Archives of General Psychiatry, 48, 1089-1096.

Bailey, J. M., Pillard, R. C., Neale, M. C. & Agyei, Y. (1993). Heritable factors influence sexual orientation in women. Archives of General Psychology, 50, 217-223.

Baldridge, D.C., Eddleston, K.A., & Vega, J.F. (2006). Saying no to being uprooted: The impact of family and gender on willingness to relocate. Journal of Occupational and Organizational Psychology, 79, 131-149.

Balthazart, J. (2018). Fraternal birth order effect on sexual orientation explained. Proceedings of the National Academy of Sciences of the United States of America, 115(2), 234-236.

Bartholomew, K. (1990). Avoidance of intimacy: An attachment perspective. Journal of Social and Personal Relationships, 7, 147-178. DOI: 10.1037/0022-3524.61.2.226.

Basseches, M. (1984). Dialectical thinking and adult development. Norwood, NJ: Ablex Pub.

Bauermeister, J. A., Johns, M. M., Sandfort, T. G., Eisenberg, A., Grossman, A. H., & D’Augelli, A. R. (2010). Relationship trajectories and psychological well-being among sexual minority youth. Journal of Youth and Adolescence, 39(10), 1148-1163.

Belsky, J. (1984). The determinants of parenting: A process model. Child Development, 55, 83–96.

Benokraitis, N. V. (2005). Marriages and families: Changes, choices, and constraints (5th ed.). Upper Saddle River, NJ: Pearson.

Berger, K. S. (2005). The developing person through the life span (6th ed.). New York: Worth.

Bisson, M. A., & Levine, T. R. (2009). Negotiating a friends with benefits relationship. Archives of Sexual Behavior, 38, 66–73. doi:10.1007/s10508-007-9211-2

Blanchard, R. (2001). Fraternal birth order and the maternal immune hypothesis of male homosexuality. Hormones and Behavior, 40, 105-114.

Blau, F. D., Ferber, M. A., & Winkler, A. E. (2010). The economics of women, men and work. (6th ed.). Boston, MA: Prentice Hall.

Bogaert, A. F. (2015). Asexuality: What it is and why it matters. Journal of Sex Research, 52(4), 362-379. doi:10.1080/00224499.2015.1015713

Bogle, K. A. (2007). The shift from dating to hooking up in college: What scholars have missed. Sociology Compass, 1/2, 775– 788.

Bogle, K. A. (2008). Hooking up: Sex, dating, and relationships on campus. New York, NY: New York University Press.

Bohlin, G., & Hagekull, B. (2009). Socio-emotional development from infancy to young adulthood. Scandinavian Journal of Psychology, 50, 592-601.

Borgogna, N. C., McDermott, R. C., Aita, S. L., & Kridel, M. M. (2019). Anxiety and depression across gender and sexual minorities: Implications for transgender, gender nonconforming, pansexual, demisexual, asexual, queer and questioning individuals. Psychology of Sexual Orientation and Gender Diversity, 6(1), 54-63.

Bosson, J. K., Vandello, J., & Buckner, C. (2019). The psychology of sex and gender. Thousand Oaks, CA: Sage.

Boundless. (2016). Physical development in adulthood. Boundles Psychology. Retrieved from middle-adulthood-74/physical-development-in-adulthood-287-12822/

Bronfenbrenner, U. (1989). Ecological systems theory. In R. Vasta (Ed.), Annals of Child Development, Vol. 6 (pp. 187–251). Greenwich, CT: JAI Press.

Brooks-Gunn, J., & Lewis, M. (1981). Infant social perception: Responses to pictures of parents and strangers. Developmental Psychology, 17(5), 647–649.

Brown, A. (2019). Couples who meet online are more diverse than those who meet in other ways, largely because they’re younger. Pew Research Center. Retrieved from

Bruckmuller, S., Ryan, M.K., Floor, R., & Haslam, S.A. (2014). The glass cliff: Examining why women occupy leadership positions in precarious circumstances. In S. Kumra, R. Simpson, & R.J. Burke (Eds.), Oxford handbook of gender in organizations (pp. 314-331). New York: Oxford University Press.

Bryant, K. & Sheldon, P. (2017). Cyber dating in the age of mobile apps: Understanding motives, attitudes, and characteristics of users. American Communication Journal, 19(2), 1-15.

Bumpass, L. L. (1990). What’s happening to the family? Interactions between demographic and institutional change. Demography, 27(4), 483–498.

Butzer, B., & Campbell, L. (2008). Adult attachment, sexual satisfaction, and relationship satisfaction: A study of married couples. Personal Relationships, 15, 141-154.

Cain, S. (2012). Quiet. New York: Crown Publishing Group.

Campbell, L., Simpson, J. A., Boldry, J., & Kashy, D. A. (2005). Perceptions of conflict and support in romantic relationships: The role of attachment anxiety. Journal of Personality and Social Psychology, 88, 510-532.

Carlson, N. R. (2011). Foundations of behavioral neuroscience (8th ed.). Boston, MA: Pearson Education.

Carroll, J. L. (2007). Sexuality now: Embracing diversity (2nd ed.). Belmont, CA: Thomson Learning.

Carroll, J. L. (2016). Sexuality now: Embracing diversity (5th ed.). Boston, MA: Cengage Learning.

Ceci, S. J., & Williams, W. M. (2011). Understanding current causes of women’s under-representation in science. Proceedings of the National Academy of Science of the United States of America, 108(8), 3157-3162. doi:10.1073/pnas.1014871108

Centers for Disease Control and Prevention (2014). Reported STDs in the United States. Retrieved from

Centers for Disease Control and Prevention (2015a). Births and natality. Retrieved from

Centers for Disease Control and Prevention. (2015b). Obesity and overweight. Retrieved from

Centers for Disease Control and Prevention. (2016). Adult obesity causes and consequences. Retrieved from

Channick, R. (2019, July 9). Putting gender pay gap onto a broader stage. The Chicago Tribune, pp. 1-2.

Chappell, K. D., & Davis, K. E. (1998). Attachment, partner choice, and perception of romantic partners: An experimental test of the attachment-security hypothesis. Personal Relationships, 5, 327–342.

Chess, S., & Thomas, A. (1987). Origins and evolution of behavior disorders. Cambridge, MA: Harvard University Press.

Chopik, W. J., Edelstein, R. S., & Fraley, R. C. (2013). From the cradle to the grave: Age differences in attachment from early adulthood to old age. Journal or Personality, 81 (2), 171-183 DOI: 10.1111/j. 1467-6494.2012.00793

Cicirelli, V. (2009). Sibling relationships, later life. In D. Carr (Ed.), Encyclopedia of the life course and human development. Boston, MA: Cengage.

Clark, L. A., Kochanska, G., & Ready, R. (2000). Mothers’ personality and its interaction with child temperament as predictors of parenting behavior. Journal of Personality and Social Psychology, 79, 274–285.

Clark, L. A. & Watson, D. (1999). Temperament: A new paradigm for trait theory. In L.A. Pervin & O. P. John (Eds.), Handbook of personality. NY: Guilford.

Clarke, L., & Nichols, J. (1972). I have more fun with you than anybody. New York, NY: St. Martin’s.

Cohen, P. (2013). Marriage is declining globally. Can you say that? Retrieved from

Cohen-Bendehan, C. C., van de Beek, C. & Berenbaum, S. A. (2005). Prenatal sex hormone effects on child and adult sex-typed behavior: Methods and findings. Neuroscience and Biobehavioral Reviews, 47, 230-237.

Cohn, D. (2013). In Canada, most babies now born to women 30 and older. Pew Research Center.

Conger, R. D., & Conger, K. J. (2002). Resilience in Midwestern families: Selected findings from the first decade of a prospective longitudinal study. Journal of Marriage and Family, 64, 361–373.

Copen, C.E., Daniels, K., & Mosher, W.D. (2013) First premarital cohabitation in the United States: 2006–2010 National Survey of Family Growth. National health statistics reports; no 64. Hyattsville, MD: National Center for Health Statistics.

Council of Economic Advisors. (2015). Gender pay gap: Recent trends and explanations. Retrieved from

Crowley, K., Callanan, M. A., Tenenbaum, H. R., & Allen, E. (2001). Parents explain more often to boys than to girls during shared scientific thinking. Psychological Science, 12, 258–261.

Davidson, R. J. & Begley, S. (2012). The emotional life of your brain. New York: Penguin.

Davis, J. L., & Rusbult, C. E. (2001). Attitude alignment in close relationships. Journal of Personality & Social Psychology, 81(1), 65–84.

Demick, J. (1999). Parental development: Problem, theory, method, and practice. In R. L. Mosher, D. J. Youngman, & J. M. Day (Eds.), Human development across the life span: Educational and psychological applications (pp. 177–199). Westport, CT: Praeger.

Desai, S., & Andrist, L. (2010). Gender scripts and age at marriage in India. Demography, 47, 667-687. doi:10.1353/dem.0.0118 Desilver, D. (2016) Millions of young people in the US and EU are neither working nor learning. Pew Research Center (January 28, 2016).

Diamond, M. (2002). Sex and gender are different: Sexual identity and gender identity are different. Clinical Child Psychology and Psychiatry, 7(3), 320-334.

Douglass, C. B. (2007). From duty to desire: Emerging adulthood in Europe and its consequences. Child Development Perspectives, 1, 101–108.

Driver, J., & Gottman, J. (2004). Daily marital interactions and positive affect during marital conflict among newlywed couples. Family Process, 43, 301–314.

Dunn, J. (1984). Sibling studies and the developmental impact of critical incidents. In P.B. Baltes & O.G. Brim (Eds.), Life-span development and behavior (Vol 6). Orlando, FL: Academic Press.

Dunn, J. (2007). Siblings and socialization. In J. E. Grusec & P. D. Hastings (Eds.), Handbook of socialization. New York: Guilford.

Dye, J. L. (2010). Fertility of American women: 2008. Current Population Reports. Retrieved from

Ebrahimi, L., Amiri, M., Mohamadlou, M., & Rezapur, R. (2017). Attachment stules, parenting styles, and depression. International Journal of Mental Health, 15, 1064-1068.

Eisenberg, N., Fabes, R. A., Shepard, S. A., Guthrie, I.K., Murphy, B.C., & Reiser, M. (1999). Parental reactions to children’s negative emotions: Longitudinal relations to quality of children’s social functioning. Child Development, 70, 513-534.

Eisenberg, N., Hofer, C., Spinrad, T., Gershoff, E., Valiente, C., Losoya, S. L., Zhou, Q., Cumberland, A., Liew, J., Reiser, M., & Maxon, E. (2008). Understanding parent-adolescent conflict discussions: Concurrent and across-time prediction from youths’ dispositions and parenting. Monographs of the Society for Research in Child Development, 73, (Serial No. 290, No. 2), 1-160.

Erikson, E. H. (1950). Childhood and society. New York: Norton. Erikson, E. H. (1968). Identity: Youth and crisis. New York: Norton.

Finkel, E. J., Burnette J. L., & Scissors L. E. (2007). Vengefully ever after: Destiny beliefs, state attachment anxiety, and forgiveness. Journal of Personality and Social Psychology, 92, 871–886.

Fraley, R. C. (2013). Attachment through the life course. In R. Biswas-Diener & E. Diener (Eds), Noba textbook series: Psychology. Champaign, IL: DEF publishers. Retrieved from

Fraley, R. C., Hudson, N. W., Heffernan, M. E., & Segal, N. (2015). Are adult attachment styles categorical or dimensional? A taxometric analysis of general and relationship-specific attachment orientations. Journal of Personality and Social Psychology, 109 (2), 354-368.

Fraley, R. C., Roisman, G. I., Booth-LaForce, C., Owen, M. T., & Holland, A. S. (2013). Interpersonal and genetic origins of adult attachment styles: A longitudinal study from infancy to early adulthood. Journal of Personality and Social Psychology, 104, 8817-838.

Frazier, P. A, Byer, A. L., Fischer, A. R., Wright, D. M., & DeBord, K. A. (1996). Adult attachment style and partner choice: Correlational and experimental findings. Personal Relationships, 3, 117–136.

Freitas, A. L., Azizian, A., Travers, S., & Berry, S. A. (2005). The evaluative connotation of processing fluency: Inherently positive or moderated by motivational context? Journal of Experimental Social Psychology, 41(6), 636–644.

Frieden, T. (2011, January 14). Morbidity and Mortality Weekly Report for the Centers for Disease Control (United States, Center for Disease Control). Retrieved from

Friedman, H. S., Tucker, J. S., Tomlinson-Keasey, C., Schwartz, J. E., Wingard, D. L., & Criqui, M. H. (1993). Does childhood personality predict longevity? Journal of Personality and Social Psychology, 65, 176–185. doi:10.1037/0022- 3514.65.1.176

Fry, R. (2016). For the first time in the modern era, living with parents edges out other living arrangements for 18- to 34- year-olds. Washington, D.C.: Pew Research Center.

Fry, R. (2018). Millennials are the largest generation in the U. S. labor force. Retrieved from: tank/2018/04/11/millennials-largest-generation-us-labor-force/

Fryar, C. D., Carroll, M. D., & Ogden, C. L. (2014). Prevalence of overweight, obesity, and extreme obesity among adults: United States, 1960-1962 through 2011-2012. Retrieved from

Gallup Poll Report (2016). What millennials want from work and life. Business Journal. Retrieved from

Garcia, J. R., & Reiber, C. (2008). Hook-up behavior: A biopsychosocial perspective. The Journal of Social, Evolutionary, and Cultural Psychology, 2, 192–208.

Garcia, J. R., Reiber, C., Massey, S. G., & Merriwether, A. M. (2012). Sexual hookup culture: A review. Review of General Psychology, 16(2), 161-176. doi:10.1037/a0027911

Gates, G. J. (2011). How many people are lesbian, gay, bisexual and transgender? Retrieved from bisexual-and-transgender/

Gonzales, N. A., Coxe, S., Roosa, M. W., White, R. M. B., Knight, G. P., Zeiders, K. H., & Saenz, D. (2011). Economic hardship, neighborhood context, and parenting: Prospective effects on Mexican-American adolescent’s mental health. American Journal of Community Psychology, 47, 98–113. doi: 10.1007/s10464-010-9366-1

Gottman, J. M. (1999). Couple’s handbook: Marriage Survival Kit Couple’s Workshop. Seattle, WA: Gottman Institute.

Gottman, J. M., Carrere, S., Buehlman, K. T., Coan, J. A., & Ruckstuhl, L. (2000). Predicting marital stability and divorce in newlywed couples. Journal of Family Psychology, 14(1), 42-58.

Gottman, J. M., & Levenson, R. W. (1992). Marital processes predictive of later dissolution: Behavior, physiology and health. Journal of Personality and Social Psychology, 63, 221–233.

Grello, C. M., Welsh, D. P., Harper, M. S., & Dickson, J. W. (2003). Dating and sexual relationship trajectories and adolescent functioning. Adolescent & Family Health, 3, 103–112.

Grusec, J. E., Goodnow, J. J., & Cohen, L. (1996). Household work and the development of concern for others. Developmental Psychology, 32, 999–1007.

Gurrentz, B. (2018). For young adults, cohabitation is up, and marriage is down. US. Census Bureau. Retrieved from

Gwinnell, E. (1998). Online seductions: Falling in love with strangers on the Internet. New York: Johnson Publishing.

Hales, C.M., Carroll, M.D., Fryar, C.D., & Ogden, C.L. (2017). Prevalence of obesity among adults and youth: United States, 2015–2016. NCHS data brief, no 288. Hyattsville, MD: National Center for Health Statistics.

Hamilton, B. E., Martin, J. A., & Ventura, S. J. (2011). Births: Preliminary data for 2010. National Vital Statistics Reports, 60(2).

Hyattsville, MD: U.S. Department of Health and Human Services.

Harmon-Jones, E., & Allen, J. J. B. (2001). The role of affect in the mere exposure effect: Evidence from psychophysiological and individual differences approaches. Personality & Social Psychology Bulletin, 27(7), 889–898.

Harvard Health Letter. (2012). Raising your conscientiousness. Retrieved from

Hatfield, E., & Rapson, R. L. (2006). Love and sex: Cross-cultural perspectives. New York, NY: University Press of America.

Hazan, C., & Shaver, P. (1987). Romantic love conceptualized as an attachment process. Journal of Personality and Social Psychology, 52 (3), 511-524.

Hegewisch, A., & Ellis, E. (2015). The gender wage gap by occupation 2014 and by race and ethnicity. Washington DC: Institute for Women’s Policy Research. Retrieved from occupation-2014-and-by-race-and-ethnicity.

Hendrick, C., & Hendrick, S. S. (Eds.). (2000). Close relationships: A sourcebook. Thousand Oaks, CA: Sage.

Heron, M. P., & Smith, B. L. (2007). Products – Health E Stats – Homepage. Centers for Disease Control and Prevention. Retrieved from

Hess, A. (2019). Today is the Women’s World Cup final between the US and Netherlands—here’s how much money is on the line. Retrieved from line.html

Holland, A. S., Fraley, R. C., & Roisman, G. I. (2012). Attachment styles in dating couples: Predicting relationship functioning over time. Personal Relationships, 19, 234-246. doi: 10.1111/j.1475-6811.2011.01350.x

Hudson, N. W., Fraley, R. C., Vicary, A. M., & Brumbaugh, C. C. (2012). Attachment coregulation: A longitudinal investigation of the coordination in romantic partners’ attachment styles. Manuscript under review.

Hyde, J. S., Bigler, R., Joel, D., Tate, C., & van Anders, S. (2019). The future of sex and gender in psychology: Five challenges to the gender binary. American Psychologist, 74(2), 171-193.

Hyde, J. S., Else-Quest, N. M., & Goldsmith, H. H. (2004). Children’s temperament and behavior problems predict their employed mothers’ work functioning. Child Development, 75, 580–594.

Institute for College Access & Success. (2018). Student debt and the class of 2017. Retrieved from

Janicki, D., Kamarck, T., Shiffman, S., & Gwaltney, C. (2006). Application of ecological momentary assessment to the study of marital adjustment and social interactions during daily life. Journal of Family Psychology, 20, 168–172.

John, O. P., Naumann, L. P., & Soto, C. J. (2008). Paradigm shift to the integrative Big Five trait taxonomy: History, measurement, and conceptual issues. In O. P. John, R. R. Robins, & L. A. Pervin (Eds.), Handbook of personality. Theory and research (3rd ed., pp. 114–158). New York, NY: Guilford Press. 301

John, O. P., Robins, R. W., & Pervin, L. A. (2008). Handbook of personality. Theory and research (3rd ed.). New York, NY: Guilford Press.

Kagan, J. (2002). Behavioral inhibition as a temperamental category. In R.J. Davidson, K. R. Scherer, & H. H. Goldsmith (Eds.), Handbook of affective sciences. New York: Oxford University Press.

Kerr, D. C. R., Capaldi, D. M., Pears, K. C., & Owen, L. D. (2009). A prospective three generational study of fathers’ constructive parenting: Influences from family of origin, adolescent adjustment, and offspring temperament. Developmental Psychology, 45, 1257–1275.

Kiff, C. J., Lengua, L. J., & Zalewski, M. (2011). Nature and nurturing: Parenting in the context of child temperament. Clinical Child and Family Psychology Review, 14, 251–301. doi: 10.1007/s10567011-0093-4

Kinsey, A., Pomeroy, W.B., & Martin, C. E. (1948). Sexual behavior in the human male. Philadelphia, PA: Saunders. Krebs, C., Lindquist, C., Warner, T., Fisher, B., & Martin, S. (2009). College women’s experiences with physically forced, alcohol or other drug-enabled, and drug-facilitated sexual assault before and since entering college. Journal of American College Health, 57(6), 639-649.

Kreighbaum, A. (2019). Six figures in debt for a master’s degree. Retrieved from borrowing

Laursen, B., & Jensen-Campbell, L. A. (1999). The nature and functions of social exchange in adolescent romantic relationships. In W. Furman, B. B. Brown, & C. Feiring (Eds.), The development of romantic relationships in adolescence (pp. 50– 74). New York: Cambridge University Press.

Lesthaeghe, R. J., & Surkyn, J. (1988). Cultural dynamics and economic theories of fertility change. Population and Development Review 14(1), 1–45.

Lucas, R. E. & Donnellan, A. B. (2011). Personality development across the life span: Longitudinal analyses with a national sample from Germany. Journal of Personality and Social Psychology, 101, 847–861

Madden, M. & Lenhart, A. (2006). Americans who are seeking romance use the Internet to help them in their search, but there is still widespread public concern about safety of online dating. Pew/Internet and American Life Project. Retrieved from

Mandel, H. (2013). Up the down staircase: Women’s upward mobility and the wage penalty for occupational feminization, 1970- 2007. Social Forces, 91, 1183-1207.

Manning, W. S., Giordano, P. C., & Longmore, M. A. (2006). Hooking up: The relationship contexts of “nonrelationship” sex. Journal of Adolescent Research, 21, 459–483. doi:10.1177/0743558406291692

Martinez, G., Daniels, K., & Chandra, A. (2012). Fertility of men and women aged 15-44 years in the United States: National Survey of Family Growth, 2006-2010. National Health Statistics Reports, 51(April). Hyattsville, MD: U.S., Department of Health and Human Services.

McClure, M. J., Lydon., J. E., Baccus, J., & Baldwin, M. W. (2010). A signal detection analysis of the anxiously attached at speed-dating: Being unpopular is only the first part of the problem. Personality and Social Psychology Bulletin, 36, 1024–1036.

Menkin, J. A., Robles, T. F., Wiley, J. F., & Gonzaga, G. C. (2015). Online dating across the life span: Users’ relationship goals. Psychology and Aging, 30(4), 987-993.

Mita, T. H., Dermer, M., & Knight, J. (1977). Reversed facial images and the mere-exposure hypothesis. Journal of Personality & Social Psychology, 35(8), 597–601.

National Center for Transgender Equality. (2015). National transgender discrimination survey. Retrieved from

National Conference of State Legislatures. (2017, June). Cyberbullies go catfishing. State Legislatures, 8.

National Institute on Alcohol Abuse and Alcoholism. (2015). College Drinking. Retrieved from

National Institute on Alcohol Abuse and Alcoholism. (2016). Alcohol facts and statistics. Retrieved from

National Institute on Drug Abuse. (2015). College-age and young adults. Retrieved from topics/college-age-young-adults/college-addiction-studies-programs

National Institute of Drug Abuse. (2018). College-age and young adults. Retrieved from topics/college-age-young-adults

NCHEMS. (2016a). Percent of adults 18 to 24 with a high school diploma. National Center for Higher Education Management Systems

NCHEMS. (2016b). Percent of adults 18 to 24 who are attending college. National Center for Higher Education Management Systems. Retrieved from:

NCHEMS. (2016c). Percent of adults 25 to 49 who are attending college. National Center for Higher Education Management Systems. Retrieved from:

NCHEMS. (2016d). Percent who earn a Bachelor’s degree within 6 years. National Center for Higher Education Management Systems. Retrieved from

Nelson, L. J., Badger, S., & Wu, B. (2004). The influence of culture in emerging adulthood: Perspectives of Chinese college students. International Journal of Behavioral Development, 28, 26–36.

Noland, M., Moran, T., & Kotschwar, B. (2016). Is gender diversity profitable? Evidence from a global survey. Washington, DC: Peterson Institute for International Economics. Retrieved from diversity-profitable-evidence-global-survey.

OECD. (2014). Education at a Glance 2014: United States, OECD Publishing. Retrieved from

OECD. (2015). Education at a Glance 2015: OECD Indicators, OECD Publishing. Retrieved from

Office of Adolescent Health. (2019). Prevalence of adolescent opioid misuse. Retrieved from

Oliver, M. B., & Hyde, J. S. (1993). Gender differences in sexuality: A meta-analysis. Psychological Bulletin, 114, 29–51. doi:10.1037/0033-2909.114.1.29

Organization for Economic Cooperation and Development. (2019). Youth on in employment, education, or training data. Retrieved from

Owen, J., & Fincham, F. D. (2011). Young adults’ emotional reactions after hooking up encounters. Archives of Sexual Behavior, 40, 321–330. doi:10.1007/s10508-010-9652-x

Pascarella, E.T. (2006). How college effects students: Ten directions for future research. Journal of College Student Development, 47, 508-520.

Patton, W. & McMahon, M. (1999). Career development and systems theory: A new relationship. Brooks Cole Publishers. Peterson, A. (2019, July 9). Women’s World Cup. Changes could go global. The Chicago Tribune, p. 5.

Pew Research Center. (2019). Same-sex marriage around the world. Retrieved from marriage-around-the-world/

Phinney, J. S. & Baldelomar, O. A. (2011). Identity development in multiple cultural contexts. In L. A. Jensen (Ed.), Bridging cultural and developmental psychology: New syntheses in theory, research and policy (pp. 161-186). New York, NY: Oxford University Press.

Potard, C., Courtois, R., & Rusch, E. (2008). The influences of peers on risky behavior during adolescence. European Journal of Contraception and Reproductive Health Care, 13(30, 264-270.

Prinzie, P., Stams, G. J., Dekovic, M., Reijntjes, A. H., & Belsky, J. (2009). The relations between parents’ Big Five personality factors and parenting: A meta-review. Journal of Personality and Social Psychology, 97, 351–362.

Rankin, L. A. & Kenyon, D. B. (2008). Demarcating role transitions as indicators of adulthood in the 21st century. Who are they? Journal of Adult Development, 15(2), 87-92. doi: 10.1007/s10804-007-9035-2

Reis, H. T., & Aron, A. (2008). Love: What is it, why does it matter, and how does it operate? Perspectives on Psychological Science, 3(1), 80–86.

Roberts, B. W., Kuncel, N., Shiner, R., N., Caspi, A., & Goldberg, L. R. (2007). The power of personality: The comparative validity of personality traits, socioeconomic status, and cognitive ability for predicting important life outcomes. Perspectives on Psychological Science, 2(4), 313–345. doi:10.1111/j.1745-6916.2007.00047.

Roberts, B. W., & Mroczek, D. K. (2008). Personality trait change in adulthood. Current Directions in Psychological Science, 17, 31–35.

Rosenberger, N. (2007). Rethinking emerging adulthood in Japan: Perspectives from long-term single women. Child Development Perspectives, 1, 92–95.

Rottinghaus, P. J., Coon, K. L., Gaffey, A. R., & Zytowski, D. G. (2007). Thirty-year stability and predictive validity of vocational interests. Journal of Career Assessment, 15 (1), 5-23.

Rudman, L. A. (1998). Self-promotion as a risk factor for women: The costs and benefits of counterstereotypical impression management. Journal of Personality and Social Psychology, 74(3), 629-645.

Ryan, C. L. & Bauman, K. (March 2016). Educational Attainment in the United States: 2015. U.S. Department of Commerce Economics and Statistics Administration. Retrieved from

Ryle, R. (2011). Questioning gender. Los Angeles, CA: Sage Publishing.

Schindler, I., Fagundes, C. P., & Murdock, K. W. (2010). Predictors of romantic relationship formation: Attachment style, prior relationships, and dating goals. Personal Relationships, 17, 97-105.

Schmitt, D. P., Alcalay, L., Allik, J., Ault, L., Austers, I., Bennett, K. L., . . . Zupane`ie`, A. (2003). Universal sex differences in the desire for sexual variety: Tests from 52 nations, 6 continents, and 13 islands. Journal of Personality and Social Psychology, 85, 85–104. doi:10.1037/ 0022-3514.85.1.85

Schwartz, G., Kim, R., Kolundzija, A., Rieger, G., & Sanders, A. (2010). Biodemographic and physical correlates of sexual orientation in men. Archives of Sexual Behavior, 39, 93-109.

Simpson, J. A., Collins, W. A., Tran, S., & Haydon, K. C. (2007). Attachment and the experience and expression of emotions in adult romantic relationships: A developmental perspective. Journal of Personality and Social Psychology, 92, 355–367.

Simpson, J. A., Rholes, W. S., Oriña, M. M., & Grich, J. (2002). Working models of attachment, support giving, and support seeking in a stressful situation. Personality and Social Psychology Bulletin, 28, 598-608.

Sinnott, J. D. (1998). The development of logic in adulthood. NY: Plenum Press.

Smith, A., & Anderson, M. (2016). 5 facts about online dating. Pew Research Center. Retrieved from

Smith, S., Zhang, X., Basile, K., Merrick, M., Wang, J., Kresnow, M., & Chen, J. (2018). National Intimate Partner and Sexual Violence Survey, United States, 2015. Retrieved from: brief508.pdf

Society for the Study of Emerging Adulthood (SSEA). (2016). Overview. Retrieved from

Sternberg, R. (1988). A triangular theory of love. New York: Basic.

Super, D. E. (1980). A life-span life-space approach to career development. Journal of Vocational Behavior, 13, 282-298. Tamis-LeMonda, C. S., Way, N., Hughes, D., Yoshikawa, H., Kalman, R. K., & Niwa, E. Y. (2008). Parents’ goals for children: The dynamic coexistence of individualism and collectivism in cultures and individuals. Social Development, 17, 183– 209. doi:10.1111/j.1467.9507.2007.00419.x

Tannen, D. (1990). You just don’t understand: Women and men in conversation. New York: Morrow.

Thornton, A. (2005). Reading history sideways: The fallacy and enduring impact of the developmental paradigm on family life. Chicago: University of Chicago Press.

TICAS. (2015). Student debt and the class of 2014, The Institute for College Access & Success. Retrieved from

Tye, M. H. (2006). Social inequality and well-being: Race-related stress, self-esteem, and life satisfaction among African American gay and bisexual men. Dissertation Abstracts International: Section B, 67(4-B), 0419-4217.

UNdata (2010). Gross enrollment ratio in tertiary education. United Nations Statistics Division. Retrieved November 5, 2010, from

United Nations Development Programme (UNDP). (2011). Human development report. NY: Oxford University Press.

Untied, A., Orchowski, L., Mastroleo, N., & Gidycz, C. (2012). College students’ social reactions to the victim in a hypothetical sexual assault scenario: The role of victim and perpetrator alcohol use. Violence and Victims, 27(6), 957-972.

U.S. Census Bureau. (2019). Educational attainment in the United States: 2018. Retrieved from

Violence Policy Center. (2018). More than 1,800 women murdered by men in one year, new study finds. Retrieved from

Volko, N. D. (2004, September 19). Exploring the Whys of Adolescent Drug Use. (United States, National Institute on Drug Abuse). Retrieved from

Wang, W., & Parker, K. (2014). Record share of Americans have never married: As values, economics and gender patterns change. Washington, DC: Pew Research Center. Married-Americans.pdf

Wang, W., & Taylor, P. (2011). For Millennials, parenthood trumps marriage. Washington, DC: Pew Research Center.

Welsh, D. P., Grello, C. M., & Harper, M. S. (2006). No strings attached: The nature of casual sex in college students. Journal of Sex Research, 43, 255–267. doi:10.1080/00224490609552324

Wighton, K. (2016). World’s obese population hits 640 million, according to largest ever study. Imperial College. Retrieved from

Williams, L., Kabamalan, M., & Ogena, N. (2007). Cohabitation in the Philippines: Attitudes and behaviors among young women and men. Journal of Marriage and Family, 69(5), 1244–1256.

Witt, J. (2009). SOC. New York: McGraw Hill.

World Economic Forum. (2017). Global Gender Gap Report 2017. Retrieved from:

Yu, J., & Xie, Y. (2015). Cohabitation in China: Trends and determinants. Population & Development Review, 41 (4), 607-628.

Zebrowitz, L. A., Bronstad, P. M., & Lee, H. K. (2007). The contribution of face familiarity to ingroup favoritism and stereotyping. Social Cognition, 25(2), 306–338.


Adapted from Chapter 7 from Lifespan Development: A Psychological Perspective Second Edition by Martha Lally and Suzanne Valentine-French under the Creative Commons Attribution-Noncommercial-Share Alike 3.0 unported license.

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