Chapter 1    Introduction to Personality Theory7
fei75766_ch01_001-018.indd 7  02/06/20 10:41 AMOfcourse, aclose relationship exists between atheory andahypothesis. Using 
deductive reasoning (going from thegeneral tothespecific), ascientific investigator 
canderive testable hypotheses from auseful theory andthentestthese hypotheses. 
Theresults ofthese tests—whether theysupport orcontradict thehypotheses—feed 
back intothetheory. Using inductive reasoning (going from thespecific tothegen-
eral), theinvestigator thenalters thetheory toreflect these results. Asthetheory 
grows andchanges, other hypotheses canbedrawn from it,andwhen tested theyin
turnreshape thetheory.
Taxonomy
Ataxonomy isaclassification ofthings according totheirnatural relationships. Tax-
onomies areessential forthedevelopment ofscience because without classification 
ofdatascience could notgrow. Mere classification, however, doesnotconstitute a
theory. However, taxonomies canevolve intotheories when theybegin togenerate 
testable hypotheses andexplain research findings. Forexample, Robert McCrae and
PaulCosta began theirresearch byclassifying people intofivestable personality traits. 
Eventually, thisresearch ontheBigFivetaxonomy ledtomore thanamere classifica -
tion;itbecame atheory, capable ofsuggesting hypotheses andoffering explanations 
forresearch results.
Why Different Theories?
Iftheories ofpersonality aretrulyscientific, whydowehavesomany different ones? 
Alternate theories existbecause theverynature ofatheory allows thetheorist to
make speculations from aparticular point ofview. Theorists must beasobjective as
possible when gathering data, buttheirdecisions astowhat dataarecollected and
howthese dataareinterpreted arepersonal ones. Theories arenotimmutable laws; 
theyarebuilt, notonproven facts, butonassumptions thataresubject toindividual 
interpretation.
Alltheories areareflection oftheirauthors’ personal backgrounds, childhood 
experiences, philosophy oflife,interpersonal relationships, andunique manner of
looking attheworld. Because observations arecolored byanindividual observer’s 
frame ofreference, itfollows thatthere maybemany diverse theories. Nevertheless, 
divergent theories canbeuseful. Theusefulness ofatheory doesnotdepend onits
commonsense value oronitsagreement withother theories; rather, itdepends onits
ability togenerate research andtoexplain research dataandother observations.
Perspectives in Theories of Personality
Oneoftheprimary functions ofscientific theory istodescribe andexplain how
theworld works. Psychologists attempt toexplain howhuman thoughts, emotions, 
motives, andbehaviors work. Yethuman personality issocomplex thatmany dif-
ferent perspectives havedeveloped onhowtobestexplain them. These perspectives 
make different assumptions andfocus ondifferent aspects ofbehavior. Inpsychol -
ogy,there areatleastfivemajor theoretical perspectives onwhat personality isand
howitdevelops. Wehaveorganized thebook around these fiveperspectives, onefor
eachsection ofthebook (seeTable 1.1).Final PDF to printer