Feist−Feist: Theories of
Personality, Seventh
EditionV. Learning Theories 15. Skinner: Behavioral
Analysis(^476) © The McGraw−Hill
Companies, 2009
Next, a 3-hour progressive reinforcement (PR) session began. Progressive re-
inforcement involves increasing the number of responses that are required before
reinforcement. In this case, participants had to do a repetitive motor task n-number
of times (starting with 160 and going all the way to 8,400 times) to earn either two
puffs from a cigarette or $1. Which reinforcer they chose was up to them. The idea
behind the progressive nature of the reinforcement procedure was to see how long
it took a person to stop responding (give up trying to get a cigarette or money).
This breakpoint is considered the strength of the reinforcer. If participants’ break-
point increased more than the drug condition than in baseline, they were consid-
ered responders (to the drug); if not, they were considered nonresponders. As in
the study by Tidey et al., the last session allowed participants to freely smoke as
little or as much as they wished.
The general result was that there was a small effect of d-amphetamine on in-
creasing smoking. However, there were significant individual differences, and when
one examined the effects for responders compared to nonresponders, the effect was
clear. Smoking breakpoints for the 10 responders became increasingly higher with
increased dosages of d-amphetamine, and money breakpoints became increasingly
lower. In other words, responders were willing to work harder to get cigarettes under
increasing amounts of d-amphetamine. But this pattern of results did not hold for the
eight nonresponders; d-amphetamine had no real effect on their cigarette smoking.
Possible reasons for this effect were seen in the subjective ratings of the effects of
the drug: Responders said they felt high and drowsy and that the drug had good ef-
fects. On objective measures (physiological effects), however, there was no differ-
ence between the two groups.
Although this study had no direct evidence, other research provides one
plausible explanation for the individual differences seen in d-amphetamine: It re-
sults in individual differences in sensitivities to the neurotransmitter dopamine,
which is associated with most increases in feeling good or having a positive mood.
In other words, responders are more likely to be affected by the stimulant, because
their sensitivity to dopamine is greater. To the extent that personality has a biolog-
ical basis (see Chapter 14), it can affect sensitivity to conditioning. Indeed, many
researchers consider dopamine to be the “positive reinforcement” system.
Further evidence that temperamental and biological states affect response sen-
sitivity to conditioning comes from the theory of Jeffrey Gray and Alan Pickering
and their reinforcement sensitivity theory (RST; Pickering & Gray, 1999). These two
researchers have conducted dozens of studies testing their theory, and although re-
sults are usually complex, they generally support the RST.
But the association between reinforcement sensitivities and other personality
dimensions and their interaction have only recently begun to be explored. Philip Corr
(2002), for instance, conducted one of the first studies to examine the differences in
anxiety and impulsivity and their association to response sensitivities. Reinforce-
ment sensitivity theory predicts that introverts, like highly anxious individuals,
should be more sensitive to punishment due to their strong need to avoid aversive
states. Like extraverts, highly impulsive individuals should be more sensitive to re-
ward because of their strong need to experience positive states. Moreover, in the
original formulation of the theory, the personality dimensions should operate com-
pletely independently, whereas in Corr’s reformulation they can operate somewhat
470 Part V Learning Theories