 A study looking at facial recognition in British and Finnish families with a single high-functioning autistic child found that a single change in the DNA had a major impact on face memory, with AA individuals having impaired SD scores.The frequency of the A allele varies among ethnic groups, being significantly more common among East Asians than Europeans.Several selective ligands for the oxytocin receptor have recently been developed, but close similarity between the oxytocin and related vasopressin receptors make it difficult to achieve high selectivity with peptide derivatives.