Final answer:
Studies suggest that heterosexual intercourse for males may peak in late adolescence to young adulthood, but the exact age at which it is at the highest percentage for males cannot be determined from the given information.
Step-by-step explanation:
The question regarding the age at which heterosexual intercourse is at the highest percentage for males does not have a straightforward answer, as it can vary based on cultural, social, and individual factors. However, general sexual behavior studies have revealed that sexual activity tends to increase during late adolescence and peaks in young adulthood. It is important to consider that individuals' sexual practices and frequency of sexual activity can be influenced by a range of societal expectations and personal choices. For instance, attitudes towards premarital sex and the number of sexual partners one has can be shaped by cultural norms and the presence of a sexual double standard that may permit men to have more sexual freedom than women. Statistical data and surveys can provide some insights. For example, married couples in their 30s have been found to have sex more frequently than singles, with 27% of married couples of that age group engaging in sexual activity at least twice a week. Such studies suggest that heterosexual intercourse might be most frequent among adults in their late twenties to early thirties, a time when many individuals are in committed relationships or marriages. However, concrete data specifying the exact age at which heterosexual intercourse is highest for males is not quoted here, and thus we cannot provide an exact age.