XYY syndrome

(redirected from Jacob's Syndrome)
Also found in: Medical.

XYY syndrome

the theory that a man with an extra Y-chromosome is predisposed towards violence and aggression and hence the basis, usually unsuccessful, for a defence argument.
References in periodicals archive ?
When his tutor is found dead, all the hallmark behaviours of Jacob's syndrome - not looking someone in the eye, odd movements and inappropriate actions - start looking a lot like guilt to the police.