- Review the physical and cognitive changes that accompany early and middle adulthood.
- Describe social changes in early and middle adulthood.
- Describe and differentiate longitudinal and cross-sectional research.
Until the 1970s, psychologists tended to treat adulthood as a single developmental stage, with few or no distinctions made between the various periods that we pass through between adolescence and death. Present-day psychologists realize, however, that physical, cognitive, and emotional responses continue to develop throughout life, with corresponding changes in our social needs and desires. Thus, the three stages of early adulthood, middle adulthood, and late adulthood each have their own physical, cognitive, and social challenges.
In this section, we will consider the development of our cognitive and physical aspects that occur during early adulthood and middle adulthood — roughly the ages between 25 and 45 and between 45 and 65, respectively. These stages represent a long period of time — longer, in fact, than any of the other developmental stages — and the bulk of our lives is spent in them. These are also the periods in which most of us make our most substantial contributions to society, by meeting two of Erik Erikson’s life challenges. That is, we learn to give and receive love in a close, long-term relationship, and we develop an interest in guiding the development of the next generation, often by becoming parents.
Physical and cognitive changes in early and middle adulthood
Compared with the other stages, the physical and cognitive changes that occur in the stages of early and middle adulthood are less dramatic. As individuals pass into their 30s and 40s, their recovery from muscular strain becomes more prolonged, and their sensory abilities may become somewhat diminished, at least when compared with their prime years, which usually occurs during the teens and early 20s (Panno, 2004). Visual acuity diminishes somewhat, and many people in their late 30s and early 40s begin to notice that their eyes are changing and they need eyeglasses. Adults in their 30s and 40s may also begin to suffer some hearing loss because of damage to their cilia, which are the hair cells in the inner ear (Lacher-Fougëre & Demany, 2005). Additionally, it is during middle adulthood that many people first begin to suffer from ailments such as high cholesterol, high blood pressure, and low bone density (Shelton, 2006). Corresponding to changes in our physical abilities, our cognitive and sensory abilities also seem to show some, but not dramatic, decline during this stage.
The stages of both early and middle adulthood bring about a gradual decline in fertility, particularly for women. Eventually, women experience menopause, which is the cessation of the menstrual cycle that usually occurs at around age 50. Menopause occurs because of the gradual decrease in the production of the female sex hormones, estrogen and progesterone, slows the production and release of eggs into the uterus. Women whose menstrual cycles have stopped for 12 consecutive months are considered to have entered menopause (Minkin & Wright, 2004).
Researchers have found that women’s responses to menopause are social as well as physical, and they vary substantially between both individuals and cultures. Within individuals, some women may react more negatively to menopause, worrying that they have lost their femininity and that their final chance to bear children is over, whereas other women may regard menopause more positively, focusing on the new freedom from menstrual discomfort and unwanted pregnancy. In Western cultures such as in Canada, women are likely to see menopause as a challenging and potentially negative event, whereas in India, where older women enjoy more social privileges than do younger ones, menopause is more positively regarded (Avis & Crawford, 2008).
Menopause may have evolutionary benefits. Infants have better chances of survival when their mothers are younger and have more energy to care for them, and the presence of older women who do not have children of their own to care for, but who can help out with raising grandchildren, can be beneficial to the family group. Also consistent with the idea of an evolutionary benefit of menopause is that the decline in fertility occurs primarily for women, who do most of the child care and who need the energy of youth to accomplish it. If older women were able to have children, they might not be as able to effectively care for them. Most men never completely lose their fertility, but they do experience a gradual decrease in testosterone levels, sperm count, and speed of erection and ejaculation.
Social changes in early and middle adulthood
Perhaps the major marker of adulthood is the ability to create an effective and independent life. Whereas children and adolescents are generally supported by parents, adults must make their own living and must start their own families. Furthermore, the needs of adults are different from those of younger persons.
Even though the timing of the major life events that occur in early and middle adulthood varies substantially among individuals, the events nevertheless tend to follow a general sequence, known as a social clock. The social clock refers to the culturally preferred “right time” for major life events, such as moving out of the childhood house, getting married, and having children. People who do not appear to be following the social clock (e.g., young adults who still live with their parents, individuals who never marry, and couples who choose not to have children) may be seen as unusual or deviant, and they may be stigmatized by others (DePaulo, 2006; Rook, Catalano, & Dooley, 1989).
Although they are doing it later, on average, than they did even 20 or 30 years ago, most people do eventually marry. Marriage is beneficial to the partners, both in terms of mental health and physical health. People who are married report greater life satisfaction than those who are not married and also suffer fewer health problems (Gallagher & Waite, 2001; Liu & Umberson, 2008).
Divorce is more common now than it was 50 years ago. Fluctuating between 35% and 42%, the proportion of marriages that ends in divorce has remained relatively stable during the last 20 years in Canada. Among adults under 65 who were separated or divorced in 2017, over half of them had previous marriages of longer than 10 years duration. People who lived in common-law relationships without getting married were likely to have separated much earlier in the relationship than 10 years and were also more likely to experience multiple divorces or separations than previously married people (Statistics Canada, 2019).
Parenthood also involves a major and long-lasting commitment, one that can cause substantial stress on the parents. The time and finances invested in children create stress, which frequently results in decreased marital satisfaction (Twenge, Campbell, & Foster, 2003). This decline is especially true for women, who bear the larger part of the burden of raising the children and taking care of the house, despite the fact they increasingly also work and have careers.
Despite the challenges of early and middle adulthood, the majority of middle-aged adults are not unhappy. These years are often very satisfying, as families have been established, careers have been entered into, and some percentage of life goals has been realized (Eid & Larsen, 2008).
Using a longitudinal research design to assess attachment from infancy into adulthood
You might wonder whether the attachment style displayed by infants has much influence later in life. In fact, research has found that the attachment styles of children predict their emotions and their behaviours many years later (Cassidy & Shaver, 1999). Psychologists have studied the persistence of attachment styles over time using longitudinal research designs in which individuals in the sample are followed and contacted over an extended period of time, often over multiple developmental stages.
In one such study, Everett Waters, Susan Merrick, Dominique Treboux, Judith Crowell, and Leah Albersheim (2000) examined the extent of stability and change in attachment patterns from infancy to early adulthood. In their research, 60 middle-class infants who had been tested in the strange situation at one year of age were recontacted 20 years later and interviewed using a measure of adult attachment. Waters and colleagues (Waters et al., 2000) found that 72% of the participants received the same secure versus insecure attachment classification in early adulthood as they had received as infants. The adults who changed categorization, usually from secure to insecure, were primarily those who had experienced traumatic events, such as the death or divorce of parents, severe illnesses either contracted by the parents or the children themselves, or physical or sexual abuse by a family member.
In addition to finding that people generally display the same attachment style over time, longitudinal studies have also found that the attachment classification received in infancy, as assessed using the strange situation or other measures, predicts many childhood and adult behaviours. Securely attached infants have closer, more harmonious relationships with peers, are less anxious and aggressive, and are better able to understand others’ emotions than are those who were categorized as insecure as infants (Lucas-Thompson & Clarke-Stewart, 2007). Additionally, securely attached adolescents also have more positive peer and romantic relationships than their insecurely attached counterparts (Carlson, Sroufe, & Egeland, 2004). The relationship between attachment during childhood and attachment with relationship partners in adulthood was studied longitudinally by William Chopik, Robin Edelestein, and Kevin Grimm (2019), who found that attachment security increased over time for people in relationships, and there was some reduction in anxiety and avoidance related to attachment over time. However, they noted that attachment patterns within individuals remained fairly stable over long periods of time, well into adulthood.
Conducting longitudinal research is a very difficult task, but one that has substantial rewards. When the sample is large enough and the time frame long enough, the potential findings of such a study can provide rich and important information about how people change over time and the causes of those changes. The drawbacks of longitudinal studies include the researcher commitment, cost, and the challenge of finding a large sample that can be tracked over time. The loss of participants who drop out of the study is called attrition, which negatively affects the study, and the many years that it takes to get the data is also a substantial drawback. In addition, because the results are delayed over an extended period, the research questions posed at the beginning of the study may become less relevant over time as the research continues.
Cross-sectional research designs represent an alternative to longitudinal designs. In a cross-sectional research design, age comparisons are made between samples of different people at different ages at one time. For example, a cross-sectional study of intelligence might have people of different ages in the sample. In this case, researchers would be looking for age differences in intelligence by testing everyone and then comparing, for example, the adolescents, the middle-aged adults, and the old adults.
Cross-sectional studies have a major advantage in that the researcher does not have to wait for years to pass to get results. On the other hand, the interpretation of the results in a cross-sectional study is not as clear as those from a longitudinal study, in which the same individuals are studied over time. Most important, the interpretations drawn from cross-sectional studies may be confounded by cohort effects. Cohort effects refer to the possibility that differences between people of different ages may be caused by differences that are unrelated to the changes in age. The differences might instead be due to environmental factors that affect an entire age group. For instance, in our example of intelligence, a difference in scores between the adolescents and the older people may be wrongly interpreted to mean that intelligence declines over time. However, if we examine the differences between these two cohorts, we would note that they have been differentially influenced by societal experiences, such as economic hardship, the presence of wars, or the introduction of new technology. As a result, it is difficult in cross-sectional studies such as this one to determine whether the differences between the groups are due to age or to other factors.
- It is in early and middle adulthood that muscle strength, reaction time, cardiac output, and sensory abilities begin to decline.
- One of the key signs of aging in women is the decline in fertility, culminating in menopause, which is marked by the cessation of the menstrual period.
- The different social stages in adulthood — such as marriage, parenthood, and work — are loosely determined by a social clock, a culturally recognized time for each phase.
- Longitudinal and cross-sectional studies are each used to test hypotheses about development, and each approach has advantages and disadvantages.
- Compare your behaviour, values, and attitudes regarding marriage and work to the attitudes of your parents and grandparents. In what way are your values similar? In what ways are they different?
- Draw a timeline of your own planned or preferred social clock. What factors do you think will make it more or less likely that you will be able to follow the timeline?
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Cassidy, J. E., & Shaver, P. R. E. (1999). Handbook of attachment: Theory, research, and clinical applications. New York, NY: Guilford Press.
Chopik, W. J., Edlestein, R. S., & Grimm, K. J. (2019). Longitudinal changes in attachment orientation over a 59-year period. Journal of Personality and Social Psychology, 116(94), 598-611.
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Statistics Canada. (2019). Family matters: Being separated or divorced in Canada. Retrieved from https://www150.statcan.gc.ca/n1/pub/11-627-m/11-627-m2019033-eng.htm
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