Specific Abilities: Female Advantages

 11a. Verbal Ability  

Females have higher average verbal ability than males in school students reported at .29d in a meta-analysis of American studies of more than 10 million students in grades 3 through 11, in which the female advantage increased in a linear pattern from grades 3 to 8 and then remained steady in high school (Petersen, 2018). The female advantage is also present in grammar and punctuation assessed in the Language Usage Test in the 14 to 18 year-old adolescent standardisation samples of the DAT (Differential Aptitude Test) of .43d in the United States, of .20d in 14-year-olds in Britain and .35d in 18-year-olds (Lynn, 1992). In a review of 24 large data sets (including several large representative samples of US students, working adults, and military personnel), Willingham & Cole (1997) reported that girls performed better than boys in the elementary school grades in language usage at fourth grade (d > 0.2) and at the end of high school, females performed better than males in language usage (d between 0.4 and 0.5). However, in adults, males have higher verbal ability than females at .25d assessed as the median of 42 studies of the WAIS verbal IQ, as given in Table 5.4 and consistent with the developmental theory.

11b. Verbal Fluency  Verbal fluency is the ability to produce a larger number of words in a given category (e.g., birds, dogs, etc.) in a short period of time. Kimura (1999) and Hyde (2014) have shown that females have higher verbal fluency than that of males. This female advantage has been confirmed by Colom, Juan-Espinoza, Abad & Garcia (2000) in a Spanish sample of applicants to a Spanish university (n=6879, age 23) in which females obtained a higher verbal fluency score of .15d; and further confirmed by Schaie (2005, p. 77) in a study of 4,850 American adults aged 25 to 81 in which females obtained a higher score than males of .17d, and again by Maylor, Reimers, Choi et al. (2007) who reported an adult female advantage of .18d. A recent longitudinal study of clinically normal adults found a female advantage in fluency tasks (e.g., name as many words as you can that begin with a selected letter or have a similar meaning to another word) and higher performance for males on some tests of visual-spatial abilities, with a steeper decline for men over time (McCarrey et al., 2016). However, higher verbal fluency in females has been confirmed by Kosmides, Vlahou, Panagiotaki & Kiosseoglou (2004) or by Waber, Skirrbek & Herlitz (2014), who have reported that in Northern Europe there is no sex difference and in Southern Europe males scored higher than females in verbal fluency. Despite the last two studies, most studies have reported a female advantage in verbal fluency. The likely evolutionary explanation for this is that women who produce a lot of words promote the acquisition of language in their children. 

11c. Second Language Ability  Several studies have reported that females have higher average ability than males in second language ability. A female advantage of .17d has been reported among 13-year-olds in England (Burstall, Jamieson, Cohen & Hargreaves, 1974), of .64d among 12-year-olds in Ireland (Lynn & Wilson, 1993), .20d among 12-year-olds in Israel (Lewy & Chen, 1974), .27d among 12-year-olds in Sweden (Ljung, 1965), .19d among 14-year-olds in Lebanon (El Hassan, 2001), .50d among college students in the United States (Payne & Lynn, 2011) and of .32d as the median of 17 studies in a number of countries given by Lynn & Piffer (2011). In all these studies of school students who learned the second language at school, females did not perform better than males in first language ability, consistent with the results given in Chapter 9, showing that females are not better than males in verbal abilities. 

The likely evolutionary explanation for the female advantage in second language ability is that normally in the great apes, including evolving hominids, females were exogamous. Thus, “[a]mong baboons, chimps and humans, males stay where they were born and females disperse” (Gamble, 1993, p. 115) and “[i]n the great apes, including humans, males tend to stay in their birth groups and females tend to reside in the birth group of their mate” (Geary, 1998, p. 296). These exchanges have the advantages that they strengthen alliances between neighbouring groups and reduce inbreeding and the numerous genetic disorders these cause, including an impairment of intelligence (Jensen, 1998). 

When females joined a neighbouring group by exchange or capture, they would have had to integrate with their new group, and the better they integrated, the greater their chances of survival and that of their children. The neighbouring groups that females joined would sometimes have spoken a different language. For instance, in West Africa “[t]he tribes are traditionally at war with each other and speak mutually incomprehensible languages” (Dembrovitz, 1945, p. 70). And when the Caribs (the original inhabitants of the Caribbean) defeated neighbouring groups, “[t]hey used to kill the men of conquered peoples and take the women for wives, which resulted in the men and women speaking different languages” (Muller-Lyer, 1930, p. 120). When this occurred, the ability of females to acquire the new language would have facilitated acceptance by the new group. Humans are co-operating animals. Males typically hunt for meat and share it with females and children, and females help other females in a variety of tasks, such as child rearing, food sharing and caring for one another during illness. To benefit from these co-operative activities, females joining a new group would have evolved a stronger module (an innate ability designed for a specific purpose) for the acquisition of a foreign language. A female who joined a new group but was unable to acquire its language would have found it much more difficult to gain acceptance. Men, however, who remained in their own group would have had no need of the aptitude for the acquisition of a new language.

11d. Visual Memory and 

 Memory for Object Location  Females have better average visual memory and memory for object location than that of males reported as .66d in a study by Eals & Silverman (1994) and confirmed at .58d by Barnfield (1999), at .33d by Maylor, Reimers, Choi et al. (2007) and at .31d in a meta-analysis by Archer (2019). The likely evolutionary explanation for this is that in the evolutionary environment, women specialized in foraging and gathering plant foods and this would have favored the development of accurate memory for their locations. In addition, Kimura (1999, p. 51) suggested that the female advantage may be attributable to their ability to detect small changes in the home environment because “[i]f a predator or vermin entered the home, noticing displacements of objects in domestic space could help in detection of the intruder, and so contribute to survival”. 

11e. Spelling Ability  Females have higher average spelling ability than that of males of .50d in the American and of .24d in the British standardisation samples of adolescents on the DAT (Differential Aptitude Test) (Lynn, 1992). The female advantage in the British standardisation sample increased from .09d in 14-year-olds to .39d in 18-year-olds (Lynn, 1992). Arribas-Agula, Abad, & Colom (2019) reported data for a Spanish sample giving a female advantage in spelling ability in all ages from 12 (.19d) through 18 (.11d) with no significant age trend. The greater female spelling ability is likely attributable to the female advantage in visual memory that enables them better to visualize the shape of words and hence their spelling. 

11f. Perceptual and Processing Speed  Females have higher average ability in perceptual and processing speed assessed in tasks requiring “the ability to make rapid comparisons among a number of designs (letters, numbers or pictures)” (Kimura, 1999, p. 87) and the rapid encoding of abstract symbols (Estes, 1974). The female advantage in perceptual speed is shown in the 9 studies in the WISC-III, WISC-IV and WISC-V, given in Table 5.3.The female advantage in processing speed is shown in the 12 studies in the WAIS-111 and WAIS-1V with a median advantage of .12d, given in Table 5.5. The female advantage in perceptual speed is shown in the Clerical Speed and Accuracy Test in 14 to 18 year-old adolescents in the standardisation sample of the DAT (Differential Aptitude Test) of .48d in the United States (Lynn, 1992). In the British standardisation sample of the DAT (Differential Aptitude Test), the female advantage increased from .19d in 14-year-olds to .54d in 18-year-olds (Lynn, 1992). The female advantage is also present in the latent processing speed (Gs) factor in the Woodcock–Johnson Tests of Cognitive Abilities (Keith, Reynolds, Patel & Ridley, 2008). Maitland et al. (2000) reported a study of sex differences in processing speed across the adult life span in three age categories of younger (22–49), middle-aged (50–63) and older (64–87). They found that women in the younger and middle-aged groups performed better than men in processing speed, and across all age groups, women performed better than men on verbal recall. 

11g. Reading Ability and Comprehension  Females have higher ability than males in reading ability and comprehension in a number of studies summarized by Halpern (2012, pp. 123f) and confirmed in America’s National Assessment of Educational Progress (Reilly, Neumann & Andrews, 2018) and in a meta-analysis of American studies at .19d by Petersen (2018). Higher female reading ability of .18d has also been found in a large sample of 149,465 German 9-year-olds by Loesche (2019). An expression of this advantage is that females have a lower prevalence of dyslexia than that of males (Arnett, Pennington, Peterson et al., 2017). The female advantage is probably a function of the greater female verbal ability given in section 11a. 

11h. Episodic Memory  Episodic memory consists of remembering past experiences such as what one did yesterday. A female advantage in most episodic memory tasks has been reported by Herlitz & Yonker (2002) and by Asperholm, Hogman, Rafi & Herlitz (2019) in a meta-analysis of 617 studies conducted between 1973 and 2013 with 1,233,921 participants. They reported a female advantage for more verbal tasks, such as words, sentences and prose, and for materials that cannot easily be placed along the verbal-spatial continuum, such as faces, odour, taste and colour, and a male advantage in more spatial tasks, such as abstract images. It has not proved possible to find studies on whether there are sex differences in episodic memory at different ages that would confirm or dis-confirm the developmental theory. The female advantage is likely attributable to the greater female verbal ability given in section 11a.

11i. Writing Ability  Females have higher writing ability than males in the United States in a review of the literature by Hedges & Nowell (1995) and confirmed by Willingham & Cole (1997) in a review of 24 large data sets (including several large representative samples of US students, working adults and military personnel) that concluded that girls performed better than boys in elementary school grades in writing and reading at fourth grade (d > 0.2), and by the end of high school, females performed better than males in writing (between .5 d and .6d). The female advantage was confirmed by Reynolds, Schreiber, Havjovsky et al. (2015) and again in the National Assessment of Educational Progress with an effect advantage of .55d among 17–18 year-olds (Reilly, Neumann & Andrews, 2018) and in a meta-analysis of American studies at .45d by Petersen (2018). These studies show that the female advantage in writing ability increases with age. The female advantage is likely attributable to the greater female verbal ability given in section 11a.

11j. Fine Motor Skills  A female advantage in fine motor skills in infants involving hand-eye coordination has been reported by Nagy, Kompagne, Orvos et al. (2007) and at older ages by Halpern (2012, p. 109). Kimura (1999, p. 37) suggested that the female advantage may be due to their better control of their fingers and in the ability to coordinate several movements into a unit, which also contributes to their advantage in perceptual and processing speed. There is no apparent evolutionary explanation for this female advantage. 

11k. Immediate Memory  Hedges & Newell (1995, Table 2) in their meta-analysis give a female advantage of .25d. However, immediate memory is measured by the digit span test in WISC and the WAIS tests and in these there is a negligible female advantage of .05d in the WISCs given in Table 5.4 and a negligible male advantage of .09d in the WAISs given in Table 5.6. 

11l. Vocabulary  It was stated by Kimura (1999, p. 91) that “[w]hen speaking first begins, girls on average articulate earlier and better than boys, and produce longer sentences. To the extent that they speak earlier, they also have larger working vocabularies at very young ages”. This contention is confirmed in studies reviewed in Chapter 3 that showed that in 4- or 5-year-olds, females have larger vocabularies than those of males. The majority of studies show that this female advantage ceases by the age of 6 years. This was confirmed by Lynn & Cheng (2021) in a study showing that girls obtained statistically significantly higher means on vocabulary at the ages of 3 and 5 years but not among 14-year-olds, as shown in Table 6.2. 

The evidence on this was reviewed more than half a century ago by Tyler (1965, p. 144), who concluded that “[o]n vocabulary, the sex groups have turned out not to differ significantly”. This conclusion has been confirmed in a number of subsequent studies. Hyde & Linn’s (1988) meta-analysis of 40 American studies gave a negligible female advantage of .02d. Hedges & Newell (1995, Table 2) in a subsequent meta-analysis gave a negligible male advantage of .02d. Salthouse (2004) gave a negligible male advantage of .03d, derived as the average of 33 studies of samples aged from 19 to 95 years, and more recently Hyde (2014) gave a negligible female advantage of .02d. All four of these results are effectively zero. This was confirmed in the American General Social Survey (2019) which gives a zero sex difference in the knowledge of 10 words in Wordsum. There was no sex difference in vocabulary in the United Kingdom in the standardisation samples of the Mill Hill Vocabulary Scale (mean age 12.5 years, d=.0; Raven, 2008a) and in a further sample on the Mill Hill Vocabulary Scale (mean age 10.5 years, d=.0; Raven, 2008b). 

There have been some contrary results. A study of a sample of 5,389 Nigerian public school students aged 11 to 19 years on the British Mill Hill Vocabulary Scale reported that females obtained a significantly higher score than males of .11d (Lynn & Hur, 2021). There have also been some studies that have reported larger vocabulary scores in males than in females. A large male advantage of .26d was reported on the norms (n=210) for adults aged 25 to 88 years on the Boston Naming Test (Tombaugh & Hubley, 1997). This test consists of 60 pictures of objects that have to be named in decreasing order of word frequency from “bed” to “abacus”. A small male advantage has been reported in Belgium on the Boston Naming Test (n=371, mean age 9 years, d=.08; Storms, Saerens & De Deyn, 2004) and in England in a sample on the Mill Hill Vocabulary Scale (n= 2000, mean age 9 years, d=.10; Dunstan & Roberts, 1955). In the vocabulary subtest of the Wechslers, males obtained negligibly higher median scores than females of .04d in the WPPSIs given in Table 5.1, of .01d in the WISCs given in Table 5.4, and of .09d given in Table 5.6. The sex differences reported in these studies are inconsistent and suggest that there is virtually no sex difference in vocabulary except in infants among whom girls have a larger average vocabulary than that of boys. There is no apparent evolutionary explanation for this female advantage in vocabulary in infants. It is likely an effect of the earlier maturation of girls.

11m. Social Cognition 

 and Emotional Intelligence  Social cognition is the ability to understand what other people are thinking and is a designated theory of mind. A female advantage in social cognition assessed by the ability to decode non-verbal cues was reported by Hall (1978) and by the ability to identify emotions by Thompson & Voyer (2014). Social cognition is associated with emotional intelligence, on which a meta-analysis by Joseph & Newman (2010) reported a female advantage of .47d. There is no apparent evolutionary explanation for this female advantage.

Richard Lynn 

Sex Differences in Intelligence ...