fei75766_ch16_495-533.indd 513  02/06/20 01:34 PM
Chapter 16    Skinner: Behavioral Analysis513
5minutes. Such schedules result inmore responses perinterval thandofixed-interval 
schedules. Forhumans, reinforcement results more often from one’s effort rather than
thepassage oftime. Forthisreason, ratioschedules aremore common thaninterval 
schedules, andthevariable-interval schedule isprobably theleastcommon ofall.
Extinction
Once learned, responses canbelostforatleastfourreasons. First, theycansimply 
beforgotten during thepassage oftime. Second, andmore likely, theycanbelost
duetotheinterference ofpreceding orsubsequent learning. Third, theycandisap -
pearduetopunishment. Afourth cause oflostlearning isextinction, defined asthe
tendency ofapreviously acquired response tobecome progressively weakened upon 
nonreinforcement.
Operant extinction takes place when anexperimenter systematically withholds 
reinforcement ofapreviously learned response untiltheprobability ofthatresponse 
diminishes tozero. Rateofoperant extinction depends largely ontheschedule of
reinforcement under which learning occurred.
Compared withresponses acquired onacontinuous schedule, behavior trained 
onanintermittent schedule ismuch more resistant toextinction. Skinner (1953) 
observed asmany as10,000 nonreinforced responses withintermittent schedules. Such 
behavior appears tobeself-perpetuating andispractically indistinguishable from func-
tionally autonomous behavior, aconcept suggested byGordon Allport anddiscussed in
Chapter 12.Ingeneral, thehigher therateofresponses perreinforcement, theslower 
therateofextinction; thefewer responses anorganism must make ortheshorter the
timebetween reinforcers, themore quickly extinction willoccur. Thisfinding suggests 
thatpraise andother reinforcers should beusedsparingly intraining children.
Extinction isseldom systematically applied tohuman behavior outside therapy 
orbehavior modification. Most ofusliveinrelatively unpredictable environments and
almost never experience themethodical withholding ofreinforcement. Thus, many of
ourbehaviors persist overalongperiod oftimebecause theyarebeing intermittently 
reinforced, eventhough thenature ofthatreinforcement maybeobscure tous.
The Human Organism
Ourdiscussion ofSkinnerian theory tothispoint hasdealt primarily withthetechnol -
ogyofbehavior, atechnology based exclusively onthestudy ofanimals. Butdothe
principles ofbehavior gleaned from ratsandpigeons apply tothehuman organism? 
Skinner’s (1974, 1987a) viewwasthatanunderstanding ofthebehavior oflaboratory 
animals cangeneralize tohuman behavior, justasphysics canbeusedtointerpret 
what isobserved inouter space andjustasanunderstanding ofbasic genetics can
helpininterpreting complex evolutionary concepts.
Skinner (1953, 1990a) agreed withJohn Watson (1913) thatpsychology must be
confined toascientific study ofobservable phenomena, namely behavior. Science must 
begin withthesimple andmove tothemore complex. Thissequence might proceed 
from thebehavior ofanimals tothatofpsychotics, tothatofmentally challenged chil-
dren, thentothatofother children, andfinally tothecomplex behavior ofadults. Skin-
ner(1974, 1987a), therefore, made noapology forbeginning withthestudy ofanimals.Final PDF to printer