woman or a man who is sensitive to others, nurturing, and emotionally expressive (tra- ditionally feminine traits) and strong, independent, and competitive (masculine traits) would be considered to be androgynous. There is considerable evidence that androgy- nous people who possess both positive male and female characteristics are more likely to adapt well to a variety of situations, because they are more fl exible in their approach to life’s demands (Woodhill & Samuels, 2004).
Gender Similarities and Gender Differences
Do women and men differ in their psychological differences in important ways? This is not always an easy issue to discuss. Many people are concerned that information on differences between the sexes would encourage a sexist view of women. In contrast, psychologists Alice Eagly (1995) and Diane Halpern (2004) have argued that knowl- edge of gender differences is essential. They advocate the study and discussion of the psychological differences between females and males, as long as we remember that
“different” does not mean “inferior.”
In this section, we summarize hundreds of studies of gender differences. Only differences that have been replicated in multiple studies are presented. As you read this section, please note that average differences between females and males are being described in this section. This is an extremely important point, because many women and men differ considerably from the “average” for their genders. The only fair way to deal with people—males or females—is to evaluate them one person at a time without regard to what is average for their gender.
Gender Differences in Physical Characteristics. Only women can be preg- nant, give birth, and breastfeed infants. In addition, on the average, men have greater upper-body strength than women. Men can throw objects farther, on average, and with greater accuracy (Buss, 1995; Hyde, 2007). Gender differences in strength and throw- ing are of little importance in contemporary life. Yet, as we will see later in this chap- ter, many psychologists believe that physical differences played an important role in the origins of psychological gender differences (Buss, 1995; Eagly & Wood, 1999;
Wood & Eagly, 2002).
Androgynous men and women combine the best characteristics of the stereotypical masculine and feminine roles.
Gender Differences in Cognitive Ability and Achievement. Women and men are far more similar in terms of cognitive ability and academic achievement than they are different (Else-Quest & others, 2010; Hyde, 2007; see table 4.1 ). There are no gender differences in overall intelligence or achievement in most school subjects, from English literature to psychology, but there are some areas in which women excel and some in which men excel. On average, women perform better than men do in language skills, verbal memory, perceptual speed, and fi ne motor skills, whereas men perform slightly better than women in science and social studies on average (Else-Quest & oth- ers, 2010; Halpern, 2004; Hyde, 2007; Stumpf & Stanley, 1998). Most of these gender differences are very small, but on the average, men tend to receive higher scores on tests of spatial and mechanical reasoning, the ability to mentally rotate objects, esti- mates of the speed of moving objects, and navigation through three-dimensional space (Halpern, 2004; Hyde, 2007; Stumpf & Stanley, 1998).
Before the early 1990s, males performed slightly better on average than females on tests of mathematical ability and achievement (Benbow & others, 2000; Hedges &
Nowell, 1995). However, several large studies conducted in the United States since 1990 have found no differences between females and males in mathematics (Hyde, Lind- berg, Linn, Ellis, & Williams, 2008; Lindberg, Hyde, Petersen, & Linn, 2010). There are now no differences in either the average scores or the number of very high and low scores between females and males. This suggests that changes in U.S. culture have eliminated an important barrier to educational and occupational equality. Furthermore, women receive higher school grades in mathematics courses at all grade levels. This suggests that women are actually better prepared for careers that involve mathematics skills. Women, however, are less likely to be interested in careers based on mathematics (Ceci & others, 2010) and tend to attribute their success in mathematics courses to hard work, whereas men are more likely to attribute their success to their intellectual abil- ity (Kimball, 1989). These differences in career interests and the way women and men think about their success in mathematics courses may play important roles in how they approach careers that involve mathematics (Ceci & others, 2010; Nosek & others, 2002).
Much the same thinking applies to differences in cognitive ability in which women have the advantage. Although men score only slightly lower on tests of reading and spelling on average, men are twice as likely to fall in the lowest 10% of reading scores (Hedges & Nowell, 1995). No one should assume that a given person is or is not pro- fi cient in reading and spelling on the basis of gender, of course.
Gender Differences in Emotion and Social Behavior. Gender differences in social and emotional functioning tend to be larger than gender differences in cognitive performance (Bjorklund & Kipp, 1996; Eagly & Wood, 1999; Hyde, 2007; Keenan &
Shaw, 1997). On average, women are more likely than men to be nurturing, friendly, Table 4.1 Consistently Identifi ed
Gender Differences in Cognitive Ability and Achievement
On the Average, Women Score Higher than Men on Tests of:
On the Average, Men Score Higher than Women on Tests of:
Language skills Reading comprehension Spelling
Verbal memory Perceptual speed Fine motor skills
Spatial and mechanical reasoning
Science achievement Spatial memory
Social studies achievement
Electronics, automotive, and shop skills
Sources: Benbow & others, 2000; Buss, 1995; Eagly, 1995; Eagly & Wood, 1999; Else-Quest & others, 2010; Halpern, 1997;
Hedges & Nowell, 1995; Herlitz & Rehnman, 2008; Hyde & Plant, 1995; Keenan & Shaw, 1997; Seidlitz & Diener, 1998;
Steele, 1997; Stumpf & Stanley, 1998.
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Table 4.2 Consistently Identifi ed Gender Differences in Emotion and Social Behavior
On the Average, Women Are More Likely To
On the Average, Men Are More Likely To
Be nurturing and sympathetic Be sociable and friendly Be trusting and open
Be cooperative and conciliatory Engage in indirect verbal aggression Be anxious or depressed
Be better able to hide their emotions Have a social and artistic interests
Be competitive and dominant Be assertive
Commit most kinds of crimes (especially sex crimes)
Be unafraid of risks
Engage in unprovoked physical aggression Have high self-esteem
Have realistic and investigative interests
Sources: Bettencourt & Miller, 1996; Bjorklund & Kipp, 1996; Byrnes, Miller, & Schafer, 1999; Dindia & Allen, 1992; Eagly, 1995, 2009; Eagly & Wood, 1999; Feingold, 1994; Hyde & Plant, 1995; Keenan & Shaw, 1997; Kling & others, 1999; Knight, Fabes, & Higgins, 1996; Su & others, 2009.
helpful, open, trusting, cooperative, and able to conceal their emotions ( table 4.2 ). As a result, women are more interested in careers in which they can work with or help others (Diekman & others, in press). In contrast, men are more likely to be competi- tive, dominant, assertive and interested in careers in science, engineering, and math- ematics (Diekman & others, in press; Eagly & others, 2004). Women tend to like one another more than men do (Rudman & Goodwin, 2004), but women are more likely to be anxious, depressed, and have low self-esteem. Men, in contrast, are more likely to engage in physical aggression and risky behavior and are more likely to commit most kinds of crimes (Bjorklund & Kipp, 1996; Eagly & Wood, 1999; Keenan & Shaw, 1997). Remember that these are just average differences. Even though most of these gender differences are moderately large, there are many exceptions to the rule. There are many nurturing and cooperative men and many highly competitive and aggressive women. Knowing a person’s gender is not a reliable indicator of his or her cognitive abilities or personality.
Gender Differences in Mating and Sexual Behavior. Across many cul- tures, men think about sex more often, masturbate more often, and prefer to have sex more frequently than women do (Hyde, 2007; Peplau, 2003; Peterson & Hyde, 2010).
As shown in table 4.3 , women and men in many cultures also differ in other ways
Table 4.3 Consistently Identifi ed Gender Differences in Mating and Sexual Behavior
On the Average, Women Are More Likely To
On the Average, Men Are More Likely To
Prefer an older mate
Prefer a mate who has high earning potential
Prefer a partner of good character Be threatened more by emotional infi delity Restrict sex to potential long-term partners
Prefer a younger mate
Prefer a mate who is physically attractive
Prefer a mate with good housekeeping skills Be threatened more by sexual infi delity Feel comfortable with the idea of casual sex for themselves
Be sexually jealous and controlling of their partner
Sources: Bjorklund & Kipp, 1999; Bjorklund & Shackleford, 1999; Eagly & Wood, 1999; Oliver & Hyde, 1993; Peplau, 2003;
Schmidt, 2003; Peterson & Hyde, 2010; Puts, 2010.
related to sexual behavior and the selection of a mate (Bjorklund & Shackleford, 1999;
Buss, 1999; Eagly & Wood, 1999). On average, men prefer a mate who is younger and physically attractive and has good housekeeping skills. In addition, on average, men are sexually jealous and controlling of their partners but are more likely to feel comfortable with the idea of casual sex for themselves. Women, in contrast, tend to prefer mates who are somewhat older and who have good character and high earning potential. On the average, women say they are more threatened by the idea of their partner’s emotional infi delity (loving someone else) than their sexual infi delity, and they are more likely to be sexually intimate only with potential long-term partners (Bjorklund & Shackleford, 1999; Eagly & Wood, 1999; Peplau, 2003; Schmitt, 2003).
All this research raises a perplexing question: If men have the characteristics listed in tables 4.2 and 4.3 (if they are aggressive, unfaithful brutes who are only interested in a woman’s superfi cial beauty and cooking skills), how are women ever going to fi nd men of good character? The answer is that this research, although technically accu- rate, exaggerates the differences in men and women in sexuality and mate selection.
Although it is true that college men say that the number of different sexual partners that they would like to have over the next 30 years is higher on average than the num- ber desired by college women, most college men (48%) and college women (66%) say that they want only one sexual partner over the next 30 years (Pedersen & others, 2002). The difference in the average number of desired sex partners comes from the fact that a few men say they want very high numbers of different sex partners (10 or more), whereas almost no women say they want such high numbers of sex partners.
When married or in committed relationships, moreover, the overwhelming majority of both men and women are monogamous. Most of the gender difference in the number of sex partners is the result of a few males who prefer a very promiscuous lifestyle.
What about the assertion that men are more concerned with their partner’s sexual infi delity than emotional infi delity (caring about someone else)? A study of adult men and women (both heterosexual and homosexual) found that although men said that emotional infi delity was less important to them, when they discussed actual acts of infi delity of their partners in the past, both women and men of both sexual orientations experienced both types of infi delity as upsetting but were even more upset by emo- tional than sexual infi delity (Harris, 2002; Miller, Putcha-Bhagavatula, & Pedersen &
others, 2002).
Thus, although women and men differ in important ways, some of the prevailing views—even among scientists—of gender differences in mating behavior may exag- gerate the facts (Miller, Putcha-Bhagavatula, & Pedersen, 2002).
Origins of Gender Differences
Why are women and men different in the ways previously described? Current think- ing is dominated by two very different theories of gender differences. One view holds that inherited biological differences between women and men have evolved over thousands of years that are responsible for gender differences in behavior. A rival theory suggests that gender differences in behavior are the result of differences in social learning experiences associated with gender roles. We fi rst consider current research on sex differences in the structure of the brain and then turn our attention to the two major theories of gender differences in the next section of this chapter.
Sex Differences in the Brain. There is now consistent evidence from many brain-imaging studies demonstrating that the brain structures of men and women dif- fer in a number of ways, in addition to the gender differences in the brain that are related to reproduction (de Vries & Södersten, 2009; Schulkin, 1999). Also, consid- erable evidence from studies of both humans and nonhuman animals indicates that
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d ifferences in levels of estrogen, testosterone, and other sex hormones during gestation play an impor- tant role in the creation of gender differences in the brain that are evident during adulthood (Dohanich, 2003; Halpern, 2004; Wisniewski, 1998). On average, the cerebral cortex of men is about 10% larger than that of women from childhood through late adulthood (Collaer & Hines, 1995; Giedd & others, 1997; Hop- kin, 1995; Reiss & others, 1996). This difference is due to a greater volume of white matter (myelinated axons) in men, with no sex difference in the amount of “little gray cells” (the gray matter composed of the cell bodies of neurons) (Passe & others, 1997). The right cerebral hemisphere is slightly larger than the left hemisphere to the same degree in both sexes during childhood (Reiss & others, 1996), but by adulthood, the relative size of the right hemisphere is larger in men (Wisniewski, 1998). This is interesting, as most spatial abilities are mediated more by the right than the left hemisphere. Thus, the greater relative size of the right hemisphere in men is consistent with their better spatial abilities.
In addition, there are sex differences in the corpus callosum. This band of 200 mil- lion neurons connecting the two cerebral hemispheres grows in size during childhood as its neurons become fully encased in the myelin sheaths that speed neural impulses.
By adulthood, the corpus callosum reaches a larger size in women than men (Col- laer & Hines, 1995), possibly indicating greater integration of the two hemispheres in women (Banich, 1998). Consistent with this possibility, a fascinating gender differ- ence has been found in cortical activity during the performance of verbal tasks (Shay- witz & others, 1995). As shown in fi gure 4.5 , when adult women and men performed a rhyming task, there was activation only in the verbal areas of the left hemisphere in men (note that left and right are reversed in the images shown in fi gure 4.5 ). In con- trast, women showed activation in both cerebral hemispheres when they performed the same task. This suggests that the cerebral hemispheres function in a more inte- grated manner in women during some language tasks, perhaps because of the greater connectedness of their hemispheres through the corpus callosum. This difference is consistent with the superior language skills of women.
There are also interesting gender differences in subcortical areas of the brain.
As children grow older, the amygdala increases in size more rapidly in males than females (Giedd & others, 1997) and is larger in adult men (Collaer & Hines, 1995). In contrast, the hippocampus increases in size more rapidly in female children (Giedd &
others, 1997) and is larger in adult women (Collaer & Hines, 1995). These differences in the amygdala and hippocampus are tantalizingly consistent with some of the gender differences in behavior previously described. Although both the amygdala and the hippocampus play roles in both memory and emotion, the amygdala is more associ- ated with the expression of aggression, whereas the hippocampus plays a key role in everyday memory and in the inhibition of previously punished behavior (Gray, 1988).
Thus, the better memory performance of women and their greater inhibition and lower levels of aggression are consistent with gender differences in these key elements of the limbic system. There are also structural differences in the hypothalamus (Swaab &
Hofman, 1995) that may be relevant to gender differences in emotion.
Although the similarities between sex differences in the brain and gender differ- ences in behavior are provocative, we should not make too much of them. Both the human brain and human behavior are profoundly complex, and we are far from fully understanding the relationships between them. On the one hand, biological differences
Figure 4.5
These composite magnetic resonance images show the distribution of active areas in the brains of males (left) and females during a “rhyming task.” In males, activation is lateralized (confi ned) to the left interior frontal regions (following standard anatomic practices, left and right are reversed in these images). In females the same region is active both on the right and left.
Males
R L
Females
R L
in the anatomy and physiology of the brain certainly could be the cause of gender differences in cognition and emotion. On the other hand, sex differences in the brain could be the result of gender differences in behavior and experience. The structure of the brain is not fi xed at birth but changes throughout life, and it is well established that variations in experience can create changes in brain anatomy and physiology. Thus, it is possible that differences in the behavior and experience of females and males could produce sex differences in the brain. It is too early to choose between these two possibilities.
The term sex refers to the biological characteristics of being male or female, whereas the term gender refers to the identity and behaviors associated with being a male or a female in a given culture. Gender identity is the sense of being either male or female. Gender role refers to the behaviors that society expects of males and females. Gender roles are typically classifi ed as masculine or feminine, but a person may express high levels of both masculinity and femininity, a pattern referred to as androgyny. Males and females are far more simi- lar than different in all psychological domains, but there are average gender differences in some aspects of cognitive performance, social and emotional behavior, sexuality, and mate selection. There also are sex differences in brain anatomy and physiology at both cortical and subcortical levels, but their meaning is not yet fully clear.
There are no right or wrong answers to the following questions. They are presented to help you become an active reader and think critically about what you just read.
1. What do you think has been more important in your choice of a major and in your plans for a career—your sex or your gender?
2. Are your abilities, emotions, and sexuality typical of your gender? Do you think these patterns of behavior are the product of evolution, of learned gender roles, or both?
To be sure that you have learned the key points from the preceding section, cover the list of correct answers and try to answer each question. If you give an incorrect answer to any question, return to the page given next to the correct answer to see why your answer was not correct. Remember that these questions cover only some of the important information in this section; it is important that you make up your own questions to check your learning of other facts and concepts.
1. The set of behaviors that communicates to others the degree to which we are typi- cally masculine or feminine is referred to as our .
a) sex c) gender role
b) sexual orientation d) culture
2. A person who has both feminine and masculine gender characteristics is referred to as .
a) androgynous c) bisexual
b) polygamous d) heterosexual
3. The theory of the origin of sex differences that views psychological gender differ- ences as more likely to change in the near future is .
a) evolutionary theory b) social-role theory
Review
Thinking Critically about Psychology
Check Your Learning
Correct Answers: 1. c (p. 104), 2. a (p. 104),
3. b (p. 108)
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