Animal sexual behaviour however, is proving to be false as, "most hormones don’t influence behaviour directly. Rather, they affect thinking and emotions in variable ways (Azar, 40)." There is much more involved in sexual behaviour in the mammalian animal than oxytocin and vasopressin can explain. It is often assumed that animals do not have sex for pleasure, or alternatively that humans, pigs, bonoboes (and perhaps dolphins and one or two more species of primates) are the only species that do. This is sometimes stated as "animals mate only for reproduction". This view is considered a misconception by some scholars. Jonathan Balcombe argues that
Sex differences in humans the higher mobility of boys, accompanied by their lower rates of speech development in childhood, in comparison to girls. These different timings in maturation appear as sex differences in early age, and likely level off in later adulthood (Barbu, Cabanes, & Le Maner-Idrissi, 2011). This middle age – middle sex phenomenon might explain why meta-analytic reports and several experimental studies of verbal abilities and dominance using adult participants reported no sex differences. Statistics have been consistent in reporting that men commit more criminal acts than women. Self-reported delinquent acts are also higher for men than women across many different actions.