fei75766_ch04_107-148.indd 142  02/19/20 09:00 AM
Part II    Psychodynamic Theories142
evolutionary reason tosuspect thathumans areborn intooneof16types. Circling 
back tothefirsttheoretical critique, there isevidence fortheevolutionary roots 
ofseveral traits ofpersonality (asChapters 13,14,and15willdetail), butnotof
discrete, categorical types .
Onetheoretical criticism mostly revolves around thedebate oftypeversus trait. 
Most modern personality psychologists areconvinced (andthere ismuch empirical 
evidence tosupport them, seeChapters 13and14ofthisbook) thatpersonality 
traits arenoteither typologies orcategories (e.g., Introversion orExtraversion), but
rather theyexistonacontinuum withmost people being inthemiddle rather than
ononeextreme end(Grant, 2013; Pittenger, 2005). Personality isnotsoblack and
white astypes would suggest. Note thatthisiscurrently adebate inclinical psy-
chology aswell,withagrowing number ofpsychologists arguing against categorical 
diagnosis (e.g., someone iseither schizophrenic ornotschizophrenic). They argue 
thatdisorders arealsoonacontinuum rather thanbeing typologies orcategories. 
Indeed, partofthisdebate issimply adisagreement between twogroups whosee
personality differently (Lloyd, 2012). Ontheonesideareclinicians andpeople in
business whoaremore prone toseeing personality ascategories andontheother 
areexperimentalists whoaremore prone toseeing personality traits onacontinuum 
from alittletoalot.
Empirical Criticism
Empirical criticism oftheMBTI stems primarily from whether typologies arecon-
sistent overtime, thatis,whether theyhavetest–retest reliability. Here theargument 
isthatonemight receive anINTJ typology onemonth butanESFP afewmonths 
later(Grant, 2013). Ifthatistrue,thenhowvalid canitbesince personality is
consistent overlongperiods oftime? Tobefair,theevidence forreliability orcon-
sistency oftypes ismixed, withsome studies supporting it(Capraro &Capraro, 
2002) andothers suggesting thetest–retest reliability isquestionable (Boyle, 1995; 
Grant, 2013). ButeventheMyers–Briggs Foundation reports thatonretesting most 
people receive three offoursame-type categories 75–90% ofthetime(Reliability 
andValidity, n.d.). Critics would seethisasnotveryreliable since upto25%ofthe
people arereceiving adifferent score. TheFoundation argues thatthese changes 
occur most often onjustonedimension (notallfour) andwhen someone isnot
strongly placed inoneortheother typology tobegin with. Ofcourse, critics would 
argue thisisthepoint toviewtraits onacontinuum—most people areinthemiddle 
rather thanontheends.
Intheend,theMBTI doesagood jobofmeasuring Jung’s types andpredict -
ingcareer interests (Kennedy &Kennedy, 2004), butthere arequestions about the
validity ofplacing people incategories andtheextent towhich one’s category ortype
scores change overshort periods oftime.
The MBTI Remains Popular Despite Criticisms
A recent episode of NPR’s “Hidden Brain” focused on personality assessment. Though 
they did share some criticisms of MBTI, they also touted the usefulness of “typing” by 
presenting anecdotes of a woman finding dating success by screening on MBTI and, in Final PDF to printer