The Mixed Effects of Neurological Information and Brain Images on Perceptions of Psychopathic Wrongdoers Open Access

Marshall, Julia (2015)

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Although lawyers have increasing utilized neuroscience in the courtroom, relatively little is known about how people differentially evaluate equally valid neurological and psychological justifications of criminal behavior in a legal context. Previous studies have either exclusively examined how brain images affect ratings of a claim's scientific credibility or how mere neurological explanations alter such judgments. Relatedly, others have tested how brain-based information may influence judgments of criminal responsibility, culpability, and blameworthiness. These studies, however, have not tested how mock juror's individual differences in certain core philosophical beliefs may influence how people differentially assess neurological information in a courtroom setting. To fill this gap in the literature, the current study sought to examine how individual differences in mind-body dualism may affect how mock jurors evaluate a criminal's deserved punishment, treatability, dangerousness, and self-control when presented with informationally matched neurological or psychological research corroborating the psychopath's personality disorder. Across 761 participants, I found little evidence of a universal neuroscience bias. However, when taking into account self-reported dualism beliefs, minor differences in punishment tendencies emerged amongst highly dualist individuals. These results demonstrated that neuroscience likely does not possess the power to broadly transform all mock jurors' intuitions about deserved punishment, but the findings did lend credence to the idea that brain-based information may be disproportionality biasing people who already hold certain fundamental philosophical beliefs about the mind.

Table of Contents

1. Introduction 2

1.1. The Present Use of Neuroscience in the Courtroom and the Media 2

1.2. Overarching Methodological Issues of fMRI 7

1.3. Philosophical and Legal Issues with Incorporating Neuroscience in the Courtroom 8

1.4. The Empirical Neuroseduction Debate 10

1.5. The Present Study 18

1.6. Predictions 19

2. Method 21

2.1. Participants 21

2.2. Procedures 23

2.3. Material 23

2.3.1. Background Story 24

2.3.2. Transcript 24

2.3.3. Comprehension Questions 26

2.3.4. Sentencing and Reasoning Questions 27

2.3.5. Individual Difference Measures 28

3. Results 28

3.1. Inclusion and Data Preparation 29

3.2. Factor Analysis 29

3.3. MANOVAs 32

3.3.1. Reasoning Questions 32

3.3.2. Treatability 33

3.3.3. Dangerousness 33

3.3.4. Self-Control 33

3.3.5. Punishment Efficacy 34

3.3.5. Sentencing 35

3.4. Mind-Body Dualism 36

3.4.1. Reasoning Questions 36

3.4.2. Sentencing 36

3.5. Summary of Findings 38

4. Discussion 39

4.1. Limitations 46

4.2. Future Directions 47

References 51

Footnotes 56

Tables and Figures 57

Table 1 57

Table 2 58

Table 3 59

Table 4 59

Table 5 60

Table 6 61

Figure 1 62

Figure 2 62

Figure 3 63

Figure 4 64

Figure 5 65

Appendix 66

A.1. Pre-trial Materials 66

A.2. Neurological Explanation 67

A.3. Psychological Explanation 69

A.4. Neurological Image 71

A.5. Psychological Image 72

A.6. Neurological Condition Comprehension Questions 72

A.7. Psychological Condition Comprehension Questions 73

A.8. Sentencing Questions 73

A.9. Reasoning Questions 74

A.10. Demographic Information 75

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