Sex differences in cooperation: A meta-analytic review of social dilemmas.

Although it is commonly believed that women are kinder and more cooperative than men, there is conflicting evidence for this assertion. Current theories of sex differences in social behavior suggest that it may be useful to examine in what situations men and women are likely to differ in cooperation. Here, we derive predictions from both sociocultural and evolutionary perspectives on context-specific sex differences in cooperation, and we conduct a unique meta-analytic study of 272 effect sizes—sampled across 50 years of research—on social dilemmas to examine several potential moderators. The overall average effect size is not statistically different from zero (d = –0.05), suggesting that men and women do not differ in their overall amounts of cooperation. However, the association between sex and cooperation is moderated by several key features of the social context: Male–male interactions are more cooperative than female–female interactions (d = 0.16), yet women cooperate more than men in mixed-sex interactions (d = –0.22). In repeated interactions, men are more cooperative than women. Women were more cooperative than men in larger groups and in more recent studies, but these differences disappeared after statistically controlling for several study characteristics. We discuss these results in the context of both sociocultural and evolutionary theories of sex differences, stress the need for an integrated biosocial approach, and outline directions for future research. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Sex differences in neuropsychological performance and social functioning in schizophrenia and bipolar disorder.

Objective: To investigate sex differences in neurocognition and social functioning in schizophrenia and bipolar disorder and the possible role of sex as a moderator of this relationship. Method: Participants with schizophrenia (60 women/94 men), bipolar I disorder (55 women/51 men), and healthy controls (158 women/182 men) were assessed with an extensive neuropsychological test battery and a social functioning questionnaire. Results: We found significant main effects of sex for neuropsychological tests (p     

Sex differences in prefrontal cortical brain activity during fMRI of auditory verbal working memory.

Functional imaging studies of sex effects in working memory (WMEM) are few, despite significant normal sex differences in brain regions implicated in WMEM. This functional MRI (fMRI) study tested for sex effects in an auditory verbal WMEM task in prefrontal, parietal, cingulate, and insula regions. Fourteen healthy, right-handed community subjects were comparable between the sexes, including on WMEM performance. Per statistical parametric mapping, women exhibited greater signal intensity changes in middle, inferior, and orbital prefrontal cortices than men (corrected for multiple comparisons). A test of mixed-sex groups, comparable on performance, showed no significant differences in the hypothesized regions, providing evidence for discriminant validity for significant sex differences. The findings suggest that combining men and women in fMRI studies of cognition may obscure or bias results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in job satisfaction.

Measures of 5 separate aspects of job satisfaction gathered from 295 male workers and 163 female workers drawn from 4 different plants were analyzed with respect to the mean job satisfaction for the male and female workers. T2 analyses indicated that in 3 plants the female workers were significantly less satisfied than their male counterparts (p     

Sex and anxiety differences in eyelid conditioning.

Data concerning the relationship between eyelid conditioning performance and 2 S variables, Ss' sex, and scores on the MA scale, are examined. In studies employing standard procedures, high-anxiety Ss were superior to low-anxiety Ss in 23 of 27 comparisons, and females superior to males in 18 of 19 comparisons. In contrast, the direction of the differences was split approximately equally between high- and low-anxiety Ss and between males and females in studies in which conditioning was presented within the context of masking probability-learning task. (31 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in problem-solving performance as a function of attitude differences.

Men make significantly higher scores than women on a scale of attitudes toward problem solving. Attitude scores "have some positive relationship to performance scores." From Psyc Abstracts 36:01:1GD56C. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in predictors of adolescent smoking cessation.

Sex differences in predictors of smoking cessation were investigated among 337 male and 490 female participants in the RAND adolescent panel study. Participants reported smoking at least 11–20 times during the past year at Grade 10, with cessation defined as not smoking during the past year at Grade 12. Controlling for demographics, sex-specific analyses indicated that girls who quit smoking within 2 years had friends who smoked less frequently, perceived less parental approval of their smoking, had weaker intentions to continue smoking, used marijuana less frequently, attended fewer different schools, were more likely to have an intact nuclear family, experienced greater peer support, and rated themselves as healthier. Similar analyses for boys yielded results that were generally weaker and nonsignificant, with smoking quantity accounting for several associations in the sex-specific models. Despite these differences, interaction tests revealed significant sex differences for only three predictors. Implications of these results for understanding adolescent smoking cessation are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in cue perception in a visual scene: Investigation of cue type.

Sex differences in spatial navigation indicate that women may focus on positional, landmark cues whereas men favor Euclidean, directional cues. Some studies have investigated sex differences in proximal and distal cue use; however, sex differences in gradient (i.e., graded features) and pinpoint (i.e., single, defined) cue perception remain unexamined. In the current experiments, paired photographs were presented in which the 2nd photograph showed the same scene with cues removed (Experiment 1) or isolated (Experiment 2) from the 1st photograph. In Experiment 1, women showed less disruption of task performance than men showed following cue removal but were slowest after proximal pinpoint cue removal. Male performance was slowed by distal gradient and proximal pinpoint cue removal. In Experiment 2, women were faster than men at identifying isolated proximal and distal pinpoint cues and were more accurate at identifying isolated distal gradient and distal pinpoint cues. Better pinpoint cue perception and memory in women indicates one possible mechanism underlying female preference for landmark-based navigation strategies. Findings also show that whereas men may preferentially rely on distal gradient cues they are not better at perceiving those cues than are women. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex influence on face recognition memory moderated by presentation duration and reencoding.

Objective: It has been suggested that women have a better face recognition memory than men. Here we analyzed whether this advantage depends on a better encoding or consolidation of information and if the advantage is visible during short-term memory (STM), only, or whether it also remains evident in long-term memory (LTM). Method: We tested short- and long-term face recognition memory in 36 nonclinical participants (19 women). We varied the duration of item presentation (1, 5, and 10 s), the time of testing (immediately after the study phase, 1 hr, and 24 hr later), and the possibility to reencode items (none, immediately after the study phase, after 1 hr). Results: Women showed better overall face recognition memory than men (ηp2 = .15, p     

Higher social intelligence can impair source memory.

Source monitoring is made difficult when the similarity between candidate sources increases. The current work examines how individual differences in social intelligence and perspective-taking abilities serve to increase source similarity and thus negatively impact source memory. Strangers first engaged in a cooperative storytelling task. On each trial, a single word was shown to both participants, but only 1 participant was designated to add a story sentence, using this assigned word. As predicted, social intelligence negatively predicted performance in a subsequent source-monitoring task. In a 2nd study, preventing participants from being able to anticipate their partner’s next contribution to the story eliminated the effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in vulnerability to drug self-administration.

Recent evidence from both human and animal studies indicates that there are sex differences in all phases of the addiction process, including initiation and acquisition of use, patterns and levels of use, the progression to addiction, and relapse. This brief review summarizes a series of studies on sex differences in drug self-administration in rats on which the Wyeth Young Psychopharmacologist Award was based and relates these findings to human clinical data. Briefly, preclinical findings show that female rats acquire drug self-administration at a faster rate, work harder to obtain drug infusions, "binge" for longer initial periods of time and show a more diurnally dysregulated pattern of self-administration under extended-access conditions, and respond at higher levels under reinstatement testing conditions compared with male rats. Similar results have been reported in humans, suggesting a biological basis of sex differences in vulnerability to drug abuse. A number of biological mechanisms have been explored, and the results show that ovarian hormones play a critical role in modulating the reinforcing effects of drugs of abuse in females. Preclinical studies, in conjunction with human studies, should further inform a sex-specific model for differences in drug abuse, and such a model may be useful for developing prevention and treatment strategies for drug abuse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in impulsivity: A meta-analysis.

Men are overrepresented in socially problematic behaviors, such as aggression and criminal behavior, which have been linked to impulsivity. Our review of impulsivity is organized around the tripartite theoretical distinction between reward hypersensitivity, punishment hyposensitivity, and inadequate effortful control. Drawing on evolutionary, criminological, developmental, and personality theories, we predicted that sex differences would be most pronounced in risky activities with men demonstrating greater sensation seeking, greater reward sensitivity, and lower punishment sensitivity. We predicted a small female advantage in effortful control. We analyzed 741 effect sizes from 277 studies, including psychometric and behavioral measures. Women were consistently more punishment sensitive (d = ?0.33), but men did not show greater reward sensitivity (d = 0.01). Men showed significantly higher sensation seeking on questionnaire measures (d = 0.41) and on a behavioral risk-taking task (d = 0.36). Questionnaire measures of deficits in effortful control showed a very modest effect size in the male direction (d = 0.08). Sex differences were not found on delay discounting or executive function tasks. The results indicate a stronger sex difference in motivational rather than effortful or executive forms of behavior control. Specifically, they support evolutionary and biological theories of risk taking predicated on sex differences in punishment sensitivity. A clearer understanding of sex differences in impulsivity depends upon recognizing important distinctions between sensation seeking and impulsivity, between executive and effortful forms of control, and between impulsivity as a deficit and as a trait. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effectiveness of social reinforcement following social and sensory deprivation.

Prior to the presentation of a simple operant task, 72 boys and girls of CA 5-7 were placed in 1 of 3 deprivation conditions: (a) social and sensory, (b) social, (c) nondeprivation. The conditions differed according to the presence or absence of E and the presence or absence of interesting visual stimulation (viewing a colored, abstract film). During the 7 minutes of the experimental task Ss were socially reinforced by supportive comments twice each minute after the 1st, base-line minute. In the analysis of changes in performance following the 1st minute, significant effects were found for (a) deprivation condition (C), (b) sex of S (S), (c) age of S (A), (d) minutes (M) X S X C, and (e) M X C X A. It was concluded that isolation has differential effects on performance as a function of age and sex of S, and that the effects of isolation were related more to the sensory components of the situation than to the social components. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Explaining age differences in temporal working memory.

To determine the cognitive mechanisms underlying age differences in temporal working memory (WM), the authors examined the contributions of item memory, associative memory, simple order memory, and multiple item memory, using parallel versions of the delayed-matching-to-sample task. Older adults performed more poorly than younger adults on tests of temporal memory, but there were no age differences in nonassociative item memory, regardless of the amount of information to be learned. In contrast, a combination of associative and simple order memory, both of which were reduced in older adults, completely accounted for age-related declines in temporal memory. The authors conclude that 2 mechanisms may underlie age differences in temporal WM, namely, a generalized decline in associative ability and a specific difficulty with order information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in temporal and item memory.

Three experiments tested whether the relationship between age differences in temporal and item memory depends on the degree to which the item memory measure relies on memory for context. The authors predicted a stronger relationship of temporal memory to free recall than to recognition memory. Results showed that age differences in temporal memory could be eliminated after controlling for free recall but not recognition memory performance. Under some conditions recognition memory accounted for a significant portion of age-related variance in temporal memory. These results challenge past research that has interpreted age differences in temporal and item memory as independent and suggest that a generalized decline in context memory may underlie reduced performance in older adults on all types of memory tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in value priorities: Cross-cultural and multimethod studies.

The authors assess sex differences in the importance of 10 basic values as guiding principles. Findings from 127 samples in 70 countries (N = 77,528) reveal that men attribute consistently more importance than women do to power, stimulation, hedonism, achievement, and self-direction values; the reverse is true for benevolence and universalism values and less consistently for security values. The sexes do not differ on tradition and conformity values. Sex differences are small (median d = .15; maximum d = .32 [power]) and typically explain less variance than age and much less than culture. Culture moderates all sex differences and sample type and measurement instrument have minor influences. The authors discuss compatibility of findings with evolutionary psychology and sex role theory and propose an agenda for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in visuospatial working memory.

In two visuospatial working memory (VSWM) span experiments, older and young participants were tested under conditions of either high or low interference, using two different displays: computerized versions of a 3 × 3 matrix or the standard (randomly arrayed) Corsi block task (P. M. Corsi, 1972). Older adults' VSWM estimates were increased in the low-interference, compared with the high-interference, condition, replicating findings with verbal memory span studies. Young adults showed the opposite pattern, and together the findings suggest that typical VSWM span tasks include opposing components (interference and practice) that differentially affect young and older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in health and illness.

The literature on sex differences in illness and disease was examined. Although some biologic sex differences are thought to exist, the overlap between the sexes precluded separation of the sexes for treatment or control of problem conditions. Statistics Canada data on mental illness among males and females in Canada were also examined, and deficiencies in available information were discussed. Most notably lacking were statistics on the use of outpatient mental health services. A number of recommendations were made regarding the collection of Canadian mental health statistics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences, sex composition, and group problem solving.

Males and females solved Maier's (1952) horse trading problem while working alone or in groups. Men tended to solve the problem better individually but also to profit from group discussion. Women in mixed groups seemed better motivated to solve the problem than those in groups composed of all females. (PsycINFO Database Record (c) 2010 APA, all rights reserved)