▁lower ▁order ▁factor ▁in ▁the ▁S ES II - W ▁l abeled ▁Ar ous al ▁Cont ing ency ▁was ▁particularly ▁relevant ; ▁this ▁factor ▁explains ▁the ▁easy ▁dis ruption ▁of ▁sexual ▁ar ous al . ▁ ▁Reg ard less ▁of ▁the ▁difference ▁in ▁these ▁two ▁question na ires , ▁both ▁surve ys ' ▁scores ▁show ▁normal ▁distribution ▁ver ifying ▁the ▁hypothesis ▁that ▁there ▁is ▁a ▁normal ▁individual ▁variation ▁in ▁sexual ▁ar ous al ▁and ▁in hib ition . ▁ ▁In ▁the ▁original ▁S IS / SE S ▁question naire , ▁statist ically ▁significant ▁gender ▁differences ▁are ▁seen ▁despite ▁considerable ▁overlap ▁in ▁scores ▁between ▁men ▁and ▁women . ▁ ▁On ▁average , ▁males ▁score ▁higher ▁on ▁sexual ▁exc itation ▁and ▁lower ▁than ▁females ▁on ▁both ▁fac ets ▁of ▁sexual ▁in hib ition . ▁ ▁As ▁yet , ▁the ▁differences ▁in ▁scores ▁between ▁g enders ▁have ▁not ▁been ▁explained ▁beyond ▁the ▁theoretical ▁level . ▁▁▁ ▁The ▁source ▁of ▁individual ▁vari ability ▁on ▁the ▁sexual ▁exc itation ▁and ▁in hib ition ▁systems ▁is ▁not ▁known ▁definit ively . ▁ ▁Even ▁less ▁is ▁known ▁about ▁how ▁these ▁systems ▁develop ▁in ▁individuals . ▁ ▁Age ▁of ▁first ▁m ast urb ation ▁has ▁been ▁used ▁as ▁a ▁measure ▁to ▁assess ▁sexual ▁development . ▁Age ▁of ▁m ast urb atory ▁on set ▁is ▁much ▁more ▁variable ▁in ▁girls ▁than ▁boys , ▁whose ▁tend ▁to ▁be ▁close ▁to ▁pub ert y . ▁Research ers ▁have ▁not ▁determined ▁whether ▁this ▁gender ▁difference ▁is ▁bi ological ▁in ▁nature ▁or ▁influenced ▁by ▁soci oc