Armarjeet Sada was the world's youngest serial killer

Twin studies have also been conducted to assess the genetic link. One study conducted looked at 32 MZ twins who were reared apart, thus eliminating environmental factors. The results showed that both childhood and adult antisocial behaviour, had high heritability involved (Joseph, 2001). However, as with all twin studies we need to consider why the concordance rates between twins is not 100%.