A cikin binciken Task Force na 1996 game da Intelligence wanda ƙungiyar American Psychological Association ta tallafawa ta kammala cewa akwai bambance-bambance masu yawa a cikin IQ tsakanin jinsi. Matsalar tantance dalilan da ke haifar da wannan bambancin ya danganci batun gudummawar "yanayi da haɓaka" ga IQ. Masana ilimin halayyar mutum kamar Alan S. Kaufman da Nathan Brody da masana ilimin lissafi kamar Bernie Devlin sun yi jayayya cewa babu isassun bayanai da za a kammala cewa wannan saboda tasirin kwayoyin halitta ne. Wani labarin bita da aka buga a cikin 2012 ta manyan malamai kan hankali na mutum ya kammala, bayan nazarin bayanan bincike na baya, cewa bambancin rukuni a cikin IQ an fi fahimta a matsayin asalin muhalli.
IQ