. ▁ ▁The ▁formation ▁of ▁go ose ▁b umps ▁in ▁humans ▁under ▁stress ▁is ▁considered ▁to ▁be ▁a ▁v estig ial ▁ref lex ; ▁and ▁its ▁function ▁in ▁other ▁ap es ▁is ▁to ▁raise ▁the ▁body ' s ▁hair , ▁and ▁would ▁have ▁made ▁human ▁ancest ors ▁appear ▁larger ▁to ▁sc are ▁off ▁pred ators ▁or ▁to ▁increase ▁the ▁amount ▁of ▁air ▁tra pped ▁in ▁the ▁fur ▁to ▁make ▁it ▁more ▁ins ulating . ▁The ▁ref lex ▁of ▁producing ▁go ose ▁b umps ▁is ▁known ▁as ▁p ilo ere ction ▁or ▁the ▁pil om ot or ▁ref lex , ▁or , ▁more ▁tradition ally , ▁hor rip il ification . ▁It ▁occurs ▁in ▁many ▁m amm als ; ▁a ▁prominent ▁example ▁is ▁por cup ines , ▁which ▁raise ▁their ▁qu ills ▁when ▁threatened , ▁or ▁sea ▁ot ters ▁when ▁they ▁encounter ▁sh arks ▁or ▁other ▁pred ators . ▁ ▁Et ym ology ▁▁ ▁The ▁phrase ▁" go ose ▁b umps " ▁der ives ▁from ▁the ▁phenomen on ' s ▁association ▁with ▁go ose ▁skin . ▁Go ose ▁fe athers ▁grow ▁from ▁sp ores ▁in ▁the ▁e pid erm is ▁which ▁res emble ▁human ▁hair ▁fol lic les . ▁When ▁a ▁go ose ' s ▁fe athers ▁are ▁pl uck ed , ▁its ▁skin ▁has ▁pro tr us ions ▁where ▁the ▁fe athers ▁were , ▁and ▁these ▁b umps ▁are ▁what ▁the ▁human ▁phenomen on ▁res emb les . ▁ ▁It ▁is ▁not ▁clear ▁why ▁the ▁particular ▁f ow l , ▁go ose ,