The document summarizes two journal articles that studied psychological factors influencing attitudes toward capital punishment. The first article examined correlations between views on the insanity defense and demographic/death penalty attitudes. It found political affiliation reliably predicted insanity defense views while gender/ethnicity did not. It also found a correlation between opposing the insanity defense and overestimating its use/success rates. The second article studied how expert testimony on a defendant's mental health influenced juror death penalty views. It found labeling a defendant as psychopathic or psychotic increased perceptions of future dangerousness and likelihood of a death sentence. However, expert testimony had only a slight impact on perceptions of future dangerousness. Both studies provided insight into psychological factors shaping capital punishment

1. A Review of 2 Journal Articles on Psychological Factors Influencing Capital
Punishment Attitudes
By Oleg Nekrassovski
Capital punishment is a hot issue in the U.S., whereas in, far less criminal, Canada, it
sometimes causes private debates because majority of Canadians supposedly do not believe in
sentencing anyone, no matter how evil, to death. Since there are many potential psychological
factors which may be responsible for individual views on the subject, I decided to investigate
the recent psychological literature regarding such factors, and found two interesting articles
which are summarized below.
Bloechl et al.’s (2006) study involved a search for correlations between individual
attitudes toward the insanity defense and the previously identified factors influencing such
attitudes, such as individual demographic characteristics and individual attitudes toward death
penalty (Bloechl et al., 2006, p. 155).
A sample of 578 undergraduate students (395 females and 183 males) majoring in a
variety of subjects and being eligible for jury duty, with a mean age of 19.90 years, constituted
the participants of the study. 91.1% of the participants were Euro-Americans. 198 described
themselves as Democrats, 193 as Republicans, 159 as non-affiliated, and 28 as “other” (Bloechl
et al., 2006, p. 155).
The participants of the study completed two tests with self-explanatory names, the
Insanity Defense Attitude Scale – Revised (IDAS-R) and the Attitudes Toward the Death Penalty
Scale (ATDP), as well as the demographic questionnaire. The resulting IDAS-R scores indicated
to the authors that the participants, on average, did not support the idea of defense on the
grounds of insanity. On the other hand, the scores on the ATDP test indicated to the authors
that the participants varied significantly in their attitudes toward capital punishment. The
results of the demographic questionnaire presented each participant’s gender, ethnicity,
political affiliation, and religious beliefs. While the answers to other, relevant, questions of the
questionnaire showed that the participants greatly overestimated the extent of the use of
insanity defense and its success rate (Bloechl et al., 2006, pp. 155-156).
The influence of individual demographic characteristics and views on capital
punishment, on insanity defense attitudes, as revealed by the IDAS-R, was analyzed with
exploratory statistics (Bloechl et al., 2006, p. 156).
One statistical analysis used in the study demonstrated that the participant’s gender
was clearly an unreliable predictor of his/her attitude towards the insanity defense. The
participant’s ethnicity turned out to be equally unreliable (Bloechl et al., 2006, p. 156).
Further statistical analysis of the data overturned Tygart’s (1982, 1992) hypothesis by
demonstrating that the religious beliefs of the participants were not a reliable indicator of their

2. attitudes toward the insanity defense. Another of Tygart’s (1982, 1992) hypotheses, namely
that political affiliation is a reliable indicator of the insanity defense attitudes, was well
supported by the statistical analysis of the data in this study. Also, the analysis of data revealed
that opposition to the insanity defense strongly correlates with the overestimation of the
extent to which it is used, as well as its success rate (Bloechl et al., 2006, p. 157).
The final statistical analysis of the study analyzed the relationship between the scores
on ATDP and IDAS-R, demonstrating that there was a significant correlation between the
participants’ views on capital punishment and on defense on the grounds of insanity. In
particular, it was revealed that those participants who were the strongest supporters of capital
punishment were most strongly opposed to allowing the use of mental illness diagnosis as a
legal defense (Bloechl et al., 2006, pp. 157-158).
In spite of the seeming success of the study, the authors readily pointed out its many
limitations. The generally young age of the participants could potentially mean that the results
of the study are unique to this age group. Also, the ethnic diversity of the participants was very
different from the general American population, which may as a result have different attitudes
on the subject. Finally, this research was conducted in a non-death penalty state, a variable
which may have significantly biased the views of the participants and made the results
unrepresentative of the general American population (Bloechl et al., 2006, p. 159).
The focus of Edens et al.’s (2005) study was on testing whether (1) labeling the
defendant, by an expert witness, in a capital murder case as being psychopathic or psychotic
made the potential jurors more likely to rank him as possessing greater future danger to society
and sentence him to death, than when the same defendant was judged to be free of any
mental illness; (2) the extent of influence of expert testimony, regarding the defendant’s
mental health, on those potential jurors who already consider the defendant to be a future
danger to society, determined the extent of their support for a death sentence; (3) the extent
to which the jurors perceive the defendant in a capital murder case as being psychopathic or
psychotic, before hearing expert testimony on the subject, determined the extent of their
support for a death sentence; (4) labeling the defendant, by an expert witness, as being at a low
as compared to a high risk to engage in future violence caused a significant decrease in the
amount of future danger attributed to him by the potential jurors; (5) the more future danger is
attributed, for whatever reason, to the defendant by a potential juror, the more it is likely that
he will be sentenced to death by that same juror (Edens et al., 2005, pp. 608-609).
231 American university students taking psychology courses, constituted the
participants of the study. The mean age of the participants was 20.0 years. 64.5 % of them were
female. 93.5% were unmarried. 71.4% were Caucasian; 14.3% African American; and 10.8%
Hispanic (Edens et al., 2005, pp. 609-610).
The participants of the study were presented with a list of key facts about an actual
capital murder case, which concluded with the statement that the defendant was found guilty.

3. Next, the participants were randomly split into six groups, and presented with six different
testimonies of psychological experts regarding the defendant’s psychiatric condition. The
expert testimonies presented the defendant to the participants, depending on the group to
which they were assigned, as being either mentally healthy, psychotic, or psychopathic and
either at high or at low risk to engage in violence in the future (Edens et al., 2005, pp. 610, 612-
613).
The next step in the study asked the participants to complete a questionnaire, which
was taken from the work of Edens et al. (2004) and was aimed at identifying those participants
whose views of capital punishment or the defendant were too biased to allow them to give him
a fair sentence. As a result, all assessments of twenty five, out of the original 231 participants,
were excluded from the final data used for analysis. This group of twenty five consisted of
twenty who indicated their inability to impose a death sentence on anyone; three, who
indicated that they would sentence to death every convicted capital offender; and two, who
believed that the defendant is not guilty, even though the summary of the case, that was
presented to them, clearly stated that the defendant has confessed to the two homicides he
was accused of and that several witnesses identified him as the perpetrator of the two crimes
(Edens et al., 2005, pp. 610, 611, 613).
After the evaluation of participants’ views on death penalty and of the defendant, the
participants completed a brief questionnaire, which assessed their desire to either sentence the
defendant to death, because in their view he is clearly a future threat to society, or to life
imprisonment, because there is little reason to believe that he is prone to future acts of
violence. Also, a four-item scale from a previous study (Edens et al., 2004) was used to examine
the participants’ perception of defendant’s future dangerousness, based on the expert
testimony provided to them. Moreover, in order to assess whether the participants might have
sentenced the defendant in the way they did out of their own perceptions of his psychopathic
or psychotic inclinations, irrespective of the testimony provided, the participants were asked to
decide whether in their view the defendant was likely to exhibit the twenty specific traits from
the Hare Psychopathy Checklist – Revised (Hare, 1991, 2003) and five specific traits of
schizophrenics (Edens et al., 2005, pp. 611-612).
Statistical analysis of the collected data revealed that, on average, those participants
that were in the psychopathic- or psychotic-defendant-groups, consistently ranked him as
possessing greater future danger to society, than those participants who were in the mental-
illness-free-defendant-groups (Edens et al., 2005, p. 613). However, 60% of the participants in
the psychopathic-defendant-groups and only 30% of those in the psychotic-defendant-groups
voted for a death penalty; while among those who were in the mental-illness-free-defendant-
groups, 38% sentenced him to death (Edens et al., 2005, p. 614). On the other hand, among
those participants who already ranked the defendant as possessing considerable future danger
to society, 69% of those asked to judge a psychopathic defendant, sentenced him to death; as

4. did 57% of those dealing with a non mentally disordered defendant; and 38% of those who
dealt with a psychotic defendant (Edens et al., 2005, pp. 615-616). Also, the greater was the
extent to which the participants perceived the defendant as being psychopathic, before
considering expert testimony on the subject, the greater was the likelihood that they later
sentenced him to death (Edens et al., 2005, pp. 616, 618). It was also revealed that labeling the
defendant, through expert testimony, as being at a low as compared to a high risk to engage in
future violence caused only a slight decrease in the amount of future danger attributed to him
by the participants (Edens et al., 2005, pp. 613-614). However, the more future danger was
attributed, for whatever reason, to the defendant by a participant, the more likely he was to be
sentenced to death by that same participant (Edens et al., 2005, p. 615).
In spite of the informative nature of the results, the authors acknowledged several
limitations of their study. They pointed out that in this study they did not consider many other
factors (such as the evidence regarding defendant’s future dangerousness, the type of
information used in assessing the defendant’s mental health, or cross-examination testimony)
that could influence the decisions of the jurors exposed to the expert testimony on the
defendant’s mental health. Also, the authors pointed out that unlike real jury members, the
participants of the study were not asked to deliberate about their sentencing decisions; hence
the results of this research cover only individual decisions of would-be jurors rather than the
combined, final, decisions of whole juries (Edens et al., 2005, pp. 619-620).
The above two studies are consistent with my initial view that there are many
psychological factors which do or may influence individual attitudes toward capital punishment.
Also, the above two studies made it clear to me that these factors can only be uncovered
through controlled experiments and rigorous statistical analysis of experimental data, rather
than through conversations of opportunity.

5. References
Bloechl, A. L., Vitacco, M. J., Neumann, C. S., & Erickson, S. E. (2006). An empirical investigation
of insanity defense attitudes: exploring factors related to bias. International Journal of
Law and Psychiatry, 30, 153-161.
Edens, J.F., Colwell, L. H., Desforges, D. M., & Fernandez, K. (2005). The impact of mental health
evidence on support for capital punishment: Are defendants labeled psychopathic
considered more deserving of death? Behavioral Sciences and the Law, 23, 603-625.
Edens, J.F., Desforges, D. M., Fernandez, K. & Palac, C. A. (2004). Effects of psychopathy and
violence risk testimony on mock juror perceptions of dangerousness in a capital murder
trial. Psychology, Crime and Law, 393-412.
Hare, R. D. (1991). The Hare Psychopathy Checklist – Revised manual. Toronto: Multi-Health
Systems.
Hare, R. D. (2003). The Hare Psychopathy Checklist – Revised technical manual (2nd
ed.).
Toronto: Multi-Health Systems.
Tygart, C. E. (1982). Effects of religiosity on public opinion about legal responsibility for mentally
retarded felons. American Journal of Mental Deficiency, 86, 457-464.
Tygart, C. E. (1992). Public acceptance/rejection of insanity mental illness legal defenses for
defendants in criminal homicide cases. Journal of Psychiatry and Law, 20, 375-389.