Camilla Persson Benbow

The Science of Sex Differences in Science and Mathematics

Amid ongoing public speculation about the reasons for sex differences in careers in science and mathematics, we present a consensus statement that is based on the best available scientific evidence. Sex differences in science and math achievement and ability are smaller for the mid-range of the abilities distribution than they are for those with the highest levels of achievement and ability. Males are more variable on most measures of quantitative and visuospatial ability, which necessarily results in more males at both high- and low-ability extremes; the reasons why males are often more variable remain elusive. Successful careers in math and science require many types of cognitive abilities. Females tend to excel in verbal abilities, with large differences between females and males found when assessments include writing samples. High-level achievement in science and math requires the ability to communicate effectively and comprehend abstract ideas, so the female advantage in writing should be helpful in all academic domains. Males outperform females on most measures of visuospatial abilities, which have been implicated as contributing to sex differences on standardized exams in mathematics and science. An evolutionary account of sex differences in mathematics and science supports the conclusion that, although sex differences in math and science performance have not directly evolved, they could be indirectly related to differences in interests and specific brain and cognitive systems. We review the brain basis for sex differences in science and mathematics, describe consistent effects, and identify numerous possible correlates. Experience alters brain structures and functioning, so causal statements about brain differences and success in math and science are circular. A wide range of sociocultural forces contribute to sex differences in mathematics and science achievement and ability—including the effects of family, neighborhood, peer, and school influences; training and experience; and cultural practices. We conclude that early experience, biological factors, educational policy, and cultural context affect the number of women and men who pursue advanced study in science and math and that these effects add and interact in complex ways. There are no single or simple answers to the complex questions about sex differences in science and mathematics.

Sex differences in mathematical reasoning ability in intellectually talented preadolescents: Their nature, effects, and possible causes

Several hundred thousand intellectually talented 12-to 13-year-olds have been tested nationwide over the past 16 years with the mathematics and verbal sections of the Scholastic Aptitude Test (SAT). Although no sex differences in verbal ability have been found, there have been consistent sex differences favoring males in mathematical reasoning ability, as measured by the mathematics section of the SAT (SAT-M). These differences are most pronounced at the highest levels of mathematical reasoning, they are stable over time, and they are observed in other countries as well. The sex difference in mathematical reasoning ability can predict subsequent sex differences in achievement in mathematics and science and is therefore of practical importance. To date a primarily environmental explanation for the difference in ability has not received support from the numerous studies conducted over many years by the staff of Study of Mathematically Precocious Youth (SMPY) and others. We have studied some of the classical environmental hypotheses: attitudes toward mathematics, perceived usefulness of mathematics, confidence, expectations/ encouragement from parents and others, sex-typing, and differential course-taking. In addition, several physiological correlates of extremely high mathematical reasoning ability have been identified (left-handedness, allergies, myopia, and perhaps bilateral representation of cognitive functions and prenatal hormonal exposure). It is therefore proposed that the sex difference in SAT-M scores among intellectually talented students, which may be related to greater male variability, results from both environmental and biological factors.

Study of Mathematically Precocious Youth After 35 Years Uncovering Antecedents for the Development of Math-Science Expertise

This review provides an account of the Study of Mathematically Precocious Youth (SMPY) after 35 years of longitudinal research. Findings from recent 20-year follow-ups from three cohorts, plus 5- or 10-year findings from all five SMPY cohorts (totaling more than 5,000 participants), are presented. SMPY has devoted particular attention to uncovering personal antecedents necessary for the development of exceptional math-science careers and to developing educational interventions to facilitate learning among intellectually precocious youth. Along with mathematical gifts, high levels of spatial ability, investigative interests, and theoretical values form a particularly promising aptitude complex indicative of potential for developing scientific expertise and of sustained commitment to scientific pursuits. Special educational opportunities, however, can markedly enhance the development of talent. Moreover, extraordinary scientific accomplishments require extraordinary commitment both in and outside of school. The theory of work adjustment (TWA) is useful in conceptualizing talent identification and development and bridging interconnections among educational, counseling, and industrial psychology. The lens of TWA can clarify how some sex differences emerge in educational settings and the world of work. For example, in the SMPY cohorts, although more mathematically precocious males than females entered math-science careers, this does not necessarily imply a loss of talent because the women secured similar proportions of advanced degrees and high-level careers in areas more correspondent with the multidimensionality of their ability-preference pattern (e.g., administration, law, medicine, and the social sciences). By their mid-30s, the men and women appeared to be happy with their life choices and viewed themselves as equally successful (and objective measures support these subjective impressions). Given the ever-increasing importance of quantitative and scientific reasoning skills in modern cultures, when mathematically gifted individuals choose to pursue careers outside engineering and the physical sciences, it should be seen as a contribution to society, not a loss of talent.

Importance of Assessing Spatial Ability in Intellectually Talented Young Adolescents: A 20-Year Longitudinal Study.

At age 13, 393 boys and 170 girls scoring at the top 0.5% in general intelligence completed the Scholastic Assessment Test Mathematics (SAT-M) and Verbal (SAT-V) subtests and the Differential Aptitude Test (DAT) Space Relations (SR) and Mechanical Reasoning (MR) subtests. Longitudinal data were collected through follow-up questionnaires completed at ages 18, 23, and 33. Multivariate statistical methods were employed using the SAT-M, SAT-V, and a DAT (SR + MR) composite to predict a series of developmentally sequenced educational-vocational outcomes: (a) favorite and least favorite high school class, (b) undergraduate degree field, (c) graduate degree field, and (d) occupation at age 33. Spatial ability added incremental validity to SAT-M and SAT-V assessments in predicting educational-vocational outcomes over these successive time frames. It appears that spatial ability assessments can complement contemporary talent search procedures. The amount of lost potential for artistic, scientific, and technical disciplines that results from neglecting this critical dimension of nonverbal ideation is discussed.

Physiological correlates of extreme intellectual precocity.

Among extremely mathematically and/or verbally precocious students (top 1 in 10,000 in such reasoning ability), the following three physiological characteristics were found at high frequencies: left- or mixed-handedness, asthma and other allergies, and myopia. The first two of these may reflect the effects of a common influence (testosterone) on the nervous and immune systems during fetal development. Moreover, our results suggest that such highly able students may exhibit bihemispheric representation of cognitive functions. These results may bear on the etiology of intellectual talent.

Consequences in High School and College of Sex Differences in Mathematical Reasoning Ability: A Longitudinal Perspective

Between 1972 and 1974 the Study of Mathematically Precocious Youth (SMPY) identified over 2,000 7th and 8th graders who scored as well as a national sample of 11th and 12th grade females on the College Board’s Scholastic Aptitude Test (SAT) Mathematics or Verbal tests. A substantial sex difference in mathematical reasoning ability was found (Benbow & Stanley, 1980b, 1981). The consequences and development of this sex difference over the following 5 years were investigated longitudinally. Over 91 percent (1,996 out of 2,188 SMPY students) participated. This study established that the sex difference persisted over several years and was related to subsequent sex differences in mathematics achievement. The sex difference in mathematics did not reflect differential mathematics course taking. The abilities of males developed more rapidly than those of females. Sex differences favoring males were found in participation in mathematics, performance on the SAT-M, and taking of and performance on mathematics achievement and Advanced Placement Program examinations. SMPY females received better grades in their mathematics courses than SMPY males did. Few significant sex differences were found in attitudes toward mathematics.

States of excellence.

Research from the individual-differences tradition pertinent to the optimal development of exceptional talent is reviewed, using the theory of work adjustment (TWA) to organize fundings. The authors show how TWA concepts and psychometric methods, when used together, can facilitate positive development among talented youth by aligning learning opportunities with salient aspects of each students individuality. Longitudinal research and more general theoretical models of (adult) academic and intellectual development support this approach. This analysis also uncovers common threads running through several positive psychological concepts (e.g., effectance motivation, flow, and peak experiences). The authors conclude by underscoring some important ideals from counseling psychology for fostering intellectual development and psychological well-being. These include conducting a multifaceted assessment, focusing on strength, helping people make choices, and providing a developmental context for bridging educational and industrial psychology to facilitate positive psychological growth throughout the life span.

Top 1 in 10,000: A 10-year follow-up of the profoundly gifted

Adolescents identified before the age of 13 (N = 320) as having exceptional mathematical or verbal reasoning abilities (top 1 in 10,000) were tracked over 10 years. They pursued doctoral degrees at rates over 50 times base-rate expectations, with several participants having created noteworthy literary, scientific, or technical products by their early 20s. Early observed distinctions in intellectual strength (viz., quantitative reasoning ability over verbal reasoning ability, and vice versa) predicted sharp differences in their developmental trajectories and occupational pursuits. This special population strongly preferred educational opportunities tailored to their precocious rate of learning (i.e., appropriate developmental placement), with 95% using some form of acceleration to individualize their education.

Sex Differences in Mathematical Reasoning Ability at Age 13: Their Status 20 Years Later:

Reported is the 20-year follow-up of 1,975 mathematically gifted adolescents (top 1%) whose assessments at age 12 to 14 revealed robust gender differences in mathematical reasoning ability. Both sexes became exceptional achievers and perceived themselves as such; they reported uniformly high levels of degree attainment and satisfaction with both their career direction and their overall success. The earlier sex differences in mathematical reasoning ability did predict differential educational and occupational outcomes. The observed differences also appeared to be a function of sex differences in preferences for (a) inorganic versus organic disciplines and (b) a career-focused versus more-balanced life. Because profile differences in abilities and preferences are longitudinally stable, males probably will remain more represented in some disciplines, whereas females are likely to remain more represented in others. These data have policy implications for higher education and the world of work.

Academic Achievement in Mathematics and Science of Students between Ages 13 and 23: Are There Differences among Students in the Top One Percent of Mathematical Ability?.

The predictive validity of the Scholastic Aptitude Test-Mathematics subtest (SAT-M) was investigated for 1,996 mathematically gifted (top 1%) 7th and 8th graders. Various academic achievement criteria were assessed over a 10-year span. Individual differences in SAT-M scores obtained in junior high school predicted accomplishments in high school and college. Among students in the top 1% of ability, those with SAT-M scores in the top quarter, in comparison with those in the bottom quarter, achieved at much higher levels through high school, college, and graduate school. Of the 37 variables studied, 34 showed significant differences favoring the high SAT-M group, which were substantial