Thegroundofselectionhaschanged，untiltheaptitudeswhichnowqualifyforadmissiontotheclassarethepecuniaryaptitudesonly。Whatremainsofthepredatorybarbariantraitsisthetenacityofpurposeorconsistencyofaimwhichdistinguishedthesuccessfulpredatorybarbarianfromthepeaceablesavagewhomhesupplanted。Butthistraitcannotbesaidcharacteristicallytodistinguishthepecuniarilysuccessfulupper-classmanfromtherankandfileoftheindustrialclasses。Thetrainingandtheselectiontowhichthelatterareexposedinmodernindustriallifegiveasimilarlydecisiveweighttothistrait。Tenacityofpurposemayratherbesaidtodistinguishboththeseclassesfromtwoothers；theshiftlessne’erdo-wellandthelower-classdelinquent。Inpointofnaturalendowmentthepecuniarymancompareswiththedelinquentinmuchthesamewayastheindustrialmancompareswiththegood-naturedshiftlessdependent。Theidealpecuniarymanisliketheidealdelinquentinhisunscrupulousconversionofgoodsandpersonstohisownends，andinacallousdisregardofthefeelingsandwishesofothersandoftheremotereffectsofhisactions；butheisunlikehiminpossessingakeenersenseofstatus，andinworkingmoreconsistentlyandfarsightedlytoaremoterend。Thekinshipofthetwotypesoftemperamentisfurthershowninaproclivityto“sport“andgambling，andarelishofaimlessemulation。Theidealpecuniarymanalsoshowsacuriouskinshipwiththedelinquentinoneoftheconcomitantvariationsofthepredatoryhumannature。Thedelinquentisverycommonlyofasuperstitioushabitofmind；heisagreatbelieverinluck，spells，divinationanddestiny，andinomensandshamanisticceremony。Wherecircumstancesarefavorable，thisproclivityisapttoexpressitselfinacertainserviledevotionalfervorandapunctiliousattentiontodevoutobservances；itmayperhapsbebettercharacterizedasdevoutnessthanasreligion。Atthispointthetemperamentofthedelinquenthasmoreincommonwiththepecuniaryandleisureclassesthanwiththeindustrialmanorwiththeclassofshiftlessdependents。
Lifeinamodernindustrialcommunity，orinotherwordslifeunderthepecuniaryculture，actsbyaprocessofselectiontodevelopandconserveacertainrangeofaptitudesandpropensities。Thepresenttendencyofthisselectiveprocessisnotsimplyareversiontoagiven，immutableethnictype。Ittendsrathertoamodificationofhumannaturedifferinginsomerespectsfromanyofthetypesorvariantstransmittedoutofthepast。Theobjectivepointoftheevolutionisnotasingleone。
Thetemperamentwhichtheevolutionactstoestablishasnormaldiffersfromanyoneofthearchaicvariantsofhumannatureinitsgreaterstabilityofaim——greatersinglenessofpurposeandgreaterpersistenceineffort。Sofarasconcernseconomictheory，theobjectivepointoftheselectiveprocessisonthewholesingletothisextent；althoughthereareminortendenciesofconsiderableimportancedivergingfromthislineofdevelopment。Butapartfromthisgeneraltrendthelineofdevelopmentisnotsingle。Asconcernseconomictheory，thedevelopmentinotherrespectsrunsontwodivergentlines。Sofarasregardstheselectiveconservationofcapacitiesoraptitudesinindividuals，thesetwolinesmaybecalledthepecuniaryandtheindustrial。Asregardstheconservationofpropensities，spiritualattitude，oranimus，thetwomaybecalledtheinvidiousorself-regardingandthenon-invidiousoreconomical。
Asregardstheintellectualorcognitivebentofthetwodirectionsofgrowth，theformermayhecharacterizedasthepersonalstandpoint，ofconation，qualitativerelation，status，orworth；thelatterastheimpersonalstandpoint，ofsequence，quantitativerelation，mechanicalefficiency，oruse。
Thepecuniaryemploymentscallintoactionchieflytheformerofthesetworangesofaptitudesandpropensities，andactselectivelytoconservetheminthepopulation。Theindustrialemployments，ontheotherhand，chieflyexercisethelatterrange，andacttoconservethem。Anexhaustivepsychologicalanalysiswillshowthateachofthesetworangesofaptitudesandpropensitiesisbutthemultiformexpressionofagiventemperamentalbent。Byforceoftheunityorsinglenessoftheindividual，theaptitudes，animus，andinterestscomprisedinthefirst-namedrangebelongtogetherasexpressionsofagivenvariantofhumannature。Thelikeistrueofthelatterrange。