fei75766_ch14_435-462.indd 457  02/06/20 01:10 PM
Chapter 14    Eysenck’s Biologically Based Factor Theory 457
negative emotions (violence-fear, sadness, tension, andthreat-hostility). Participants 
wore avestthatcontinuously measured heart-rate, skinconductance (sweating), and
respiration (breathing). They alsocompleted ashort 10-item measure ofpersonal -
ity(Gosling etal.,2003). Inspired byEysenck’s theory, Brumbaugh andcolleagues 
predicted thatpeople highinneuroticism would havegreater physiological response 
toeachofthefournegative emotion scenes. They found partial support forthese 
predictions inthattheviolent-fear scene produced greater galvanic skinconductance 
(sweating) inpeople highinneuroticism thanthose lowinit.Heart rateandrespira -
tiondifferences, however, didnotexist. Other research reported thatgreater skin
conductance reactivity inpeople withhighcompared tolowlevels ofneuroticism 
peaked at4–5seconds afterthenegative stimulus anddidnotreturn tonormal for
about 9seconds (Norris, Larsen, &Cacioppo, 2007). Inthose lowinneuroticism, 
however, thepeaks weresmall andoccurred atabout 2seconds afterthestimulus and
reactivity wasbacktonormal by3–4seconds afterthestimulus. So,thereactivity is
bothstronger andlonger lasting inpeople highinneuroticism. 
Insum,thecurrent research onthebiology ofneuroticism supports Eysenck’s the-
oretical ideas going backtothe1960s, namely thatthedifferences inlimbic system and
physiology would bethefoundation forthepersonality traitofneuroticism. Tobesure,
there ismore research tobedone andnotallofthepastresearch confirms eachaspect of
Eysenck’s theory. Butoverall, abiological basisofneuroticism seems tobeestablished. 
Critique of Eysenck’s Biologically Based Theory
First, doesEysenck’s biologically based theory generate research? Onthiscriterion, it
must berated veryhigh. Figure 14.6shows thecomprehensiveness ofEysenck’s person -
alitytheory. Themiddle square embraces thepsychometric properties ofhistheory; that
is,psychoticism, extraversion, andneuroticism. Thisfigure alsoshows thatEysenck’s 
personality theory ismuch more thanasimple classification. Thegenetic andbiologi -
calantecedents ofbehavior aresuggested bythetwosquares ontheleft,whereas some 
oftheconsequences, oroutcomes, ofEysenck’s research arefound inthetwosquares 
ontheright. These consequences arearesult ofexperimental studies onconditioning, 
sensitivity, vigilance, perception, memory, andreminiscence. Areas ofresearch onsocial 
behavior areshown intheboxonthefarrightandinclude suchtopics associability, 
criminality, creativity, psychopathology, andsexual behavior. Eysenck andhiscolleagues 
havereported significant amounts ofresearch inthese andother fields ofresearch.
Second, aretraitandfactor theories falsifiable? Onthiscriterion, traitandfac-
tortheories receive amoderate tohighrating. Some ofEysenck’s research results—for 
example, hisinvestigations ofpersonality anddisease—have notbeenreplicated byout-
sideresearchers. Hisbiological theory, because itmakes specific predictions, isfalsifiable. 
Results, however, aremixed, withsome ofhispredictions being confirmed (e.g.,optimal 
arousal) andsome not(e.g.,cognitive processing speed).
Third, traitandfactor theories arerated highontheirability toorganize knowl -
edge. Because Eysenck’s model ofpersonality isoneofthefewtotakebiology seri-
ously, itisoneoftheonlytheories thatcanexplain theobservations thatindividuals 
differ inbehavior atbirth andthatgenetics accounts forroughly halfofthevariability 
inindividual differences.Final PDF to printer