Washington, Apr 29 (ANI): Whoever said ‘Men are from Mars and women from Venus’ should give a pat on his or her back, for scientists have found that sex-typed characteristics develop differently in girls and boys.

The new longitudinal study of children’s personality traits and interests, by researchers at The Pennsylvania State University, the University of Hawaii at Manoa, and Purdue University, looked at first- and second-born siblings from nearly 200 mostly White, middle-class American families.

Researchers collected information through home interviews conducted over seven years, activity diaries provided by the children, and saliva samples that measured the children’s testosterone levels.

Quite expected, they found that girls and boys differed in their sex-typed personality qualities and their sex-typed activity interests in early adolescence.

While girls showed higher levels of expressive traits (such as kindness and sensitivity) and interest in “feminine” activities (such as the arts and reading), boys displayed higher levels of instrumental traits (such as independence and adventurousness) and interest in “masculine” activities (such as sports and math).

But, the girls’ stereotypically feminine, expressive traits didn’t change over time.

On the other hand, boys’ sensitivity and warmth lessened substantially across middle childhood but increased in later adolescence so that by about age 19, boys reported about the same levels of sensitivity and warmth as girls.

For stereotypically masculine traits such as independence and adventurousness, girls showed increases only in middle childhood, but in boys, these traits rose across adolescence.

Such a pattern meant that by the end of high school, boys had many more of these characteristics than girls.

The study also found that changes in girls’ and boys’ personality traits and interests were related to how they spent their time.

Generally, girls who spent time with other females developed female personality characteristics, and boys who pursued activities with other males developed male characteristics.

However, the time spent with female peers was the exception-boys and girls who spent time with friends, who were girls, increased in independence and adventurousness.

The research also found that interests and traits developed differently in first-born children than in children born second, and second-born children showed increases in traits like adventurousness and independence across adolescence, unlike in firstborns.

Finally, it was found that children who showed faster rates of increase in the hormone testosterone in early adolescence weren’t as affected by social influences on their personality development.

The study appears in the latest issue of the journal Child Development. (ANI)