Happinessisinyourgenes，itseems，accordingtoaresearchthatshowsthemore

peopleinacountrywhohaveaparticulargene，thehappierthenationwillbe．TheFAAHgene，theDNAinquestion，makesaproteinthataffectsfeelingsofpleasureandpain．

Peoplewithaparticularversionofittendtobecheeriersouls．

Theresearchersbelievethatthefindingcanhelpexplainwhysomeoftheworld's

poorestnationsarealsothehappiest．TheteamfromBulgarialookedatwhethertherewasaconnectionbetweentheleveloftheFAAHgeneinapopulationandthenumberofpeoplewhosaidtheywereveryhappyintheglobalstudyoflifesatisfaction．Sweden，oneofthehappiestcountriesinEuropeandintheworld，haslotsofhappyDNA．Some26.3percentofSwedeshavethehappinessgene，comparedt023percentoftheBritish，21percentoftheFrenchand20percentofGermans．ThehappinessgeneisevenrarerinsouthernEurope，whereitisfoundin18percentofGreeksandjust12percentofItalians．Incontrast，thepeopleinIraqandJordanareamongtheleastlikelytoratethemselvesasveryhappyandalsohavethelowestlevelsofthegene．

Butthegeneandoptimismdon-talwaysgohandinhand．Forinstance，Russians

scoreverylowonhappiness，despitehavingtherightDNA，theJournalofHappiness

Studiesreports．Climaticdifferencesarealsofoundtobecloselyassociatedwithnationaldifferencesinhappiness．Studyco-authorMichaelMinkovsaid，"Wecannoticethehighoccurrenceofthegeneinequatorial（赤道的） andtropicalenvironmentsinSouthAmericaandAfrica，andtheloweroccurrenceofitaroundtheMediterraneanSeathaninNorthernEurope．"4'Geneticsisnottheonlydeterminingfactor （因素） ofhappiness，"Aspokesmanforthejournal'spublishersaid，"TheeconomicandpoliticaldifficultiescontinuouslyexperiencedbyEasternEuropeannationscontributetotheverylowhappinessscoresofRussians．NationsnotblessedwiththerightDNAaren'tnecessarilymiserable-happinesscanstillriseandfallforotherreasons．"

32．Theunderlinedword"it"inParagraphlrefersto___．

A．happiness

B．lifesatisfaction

C．theproteininquestion

D．theFAAHge