TheNatureofStressWeareoftenfacedwithstressorsthatareoutsideofourcontrol,fromrarenaturaldisasterstoeverydaytrafficjams.Thereisagooddealofevidencethatuncontrollableeventsareparticularlystressful.Thishasbeensh

　　TheNatureofStress

　　Weareoftenfacedwithstressorsthatareoutsideofourcontrol,fromrarenaturaldisasterstoeverydaytrafficjams.Thereisagooddealofevidencethatuncontrollableeventsareparticularlystressful.Thishasbeenshowninstudiesof“executiverats,”inwhichtworatsreceiveexactlythesameelectricshock,butoneisgivenalever（杠杆）thatcouldbeusedtoturntheshockoffafteritoccurs.Overalongseriesofsuchtrials,thepartnerrat,helplesstodoanythingaboutitspain,ismorelikelytodevelopulcers(溃疡)thanisthe“executive”.

　　Stressismostlycausedbyuncertainevents.Uncertaintyaboutaneventmakesitmoredisturbing.Onestudyfoundthatsubjectswhoweretoldthattheyhada5percentchanceofreceivinganelectricshockwereactuallymoreuneasythanthosewhoweretoldthattheyhada50percentchance.

　　Peoplemakevariousattemptstodealwiththeirstress---removingthecauseofthestress,seekingthesupportoffriendsorreinterpretingthesituationtomakeitseemlessunpleasant.RichardLazarusandhiscolleagueshavemadeausefuldistinctionbetweenproblem-focusedandemotion-focusedcopingstrategies.Problem-focusedstrategiesarethoseaimedatdoingsomethingtochangetheproblemcausingthestress. Emotion-focusedstrategiestendtoregulateourdistressingemotionalresponses.

　　PsychologistsSusanFolkmanandRichardLazarusexaminedundergraduatestudents’copingstrategiesatthreetimeperiods---twodaysbeforeamidtermexamination,aweeklatertwodaysbeforethegradeswereannounced,andfivedaysafterthegradeswereposted.Beforetheexam,studentstendedtousesuchproblem-focusedstrategiesasstudying---aguaranteedwaytoreducethepotentialproblems.Aftertheexam,whentheirfatesweresealed,iftheysoughtoutothers,itwasusuallyforemotionalsupport.

　　Likeotheranimals,humanshavealwaysbeensaferingroups.Besidesphysicalprotection,peopleprovideemotionalsupportthatcanreducethepsychologicalandphysiologicalsymptomsofstress.Alackofsupportcanincreaseoursusceptibility（敏感性）toillness.Forinstance,short-termlonelinessisassociatedwithadecreaseinimmuneresponse（免疫应答）.Incontrast,peoplewhohavestrongsocialtie