The Moral Psychology Handbook (2010), edited by John Doris, is probably the best way to become familiar with the exciting interdisciplinary field of moral psychology. The chapters are written by philosophers, psychologists, and neuroscientists. A few of them are all three, and the university department to which they are assigned is largely arbitrary.
I should also note that the chapter authors happen to comprise a large chunk of my own 'moral philosophers who don't totally suck' list. The book is also exciting because it undermines or outright falsifies a long list of popular philosophical theories with - gasp! - empirical evidence.
Chapter 1: Evolution of Morality (Machery & Mallon)
The authors examine three interpretations of the claim that morality evolved. The claims "Some components of moral psychology evolved" and "Normative cognition is a product of evolution" are empirically well-supported but philosophically uninteresting. The stronger claim that "Moral cognition (a kind of normative cognition) evolved" is more philosophically interesting, but at present not strongly supported by the evidence (according to the authors).
The chapter serves as a compact survey of recent models for the evolution of morality in humans (Joyce, Hauser, de Waal, etc.), and attempts to draw philosophical conclusions about morality from these descriptive models (e.g. Joyce, Street).
Chapter 2: Multi-system Moral Psychology (Cushman, Young, & Greene)
The authors survey the psychological and neuroscientific evidence showing that moral judgments are both intuitive/affective/unconscious and rational/cognitive/conscious, and propose a dual-process theory of moral judgment. Scientific data is used to verify or falsify philosophical theories proposed as, for example, explanations for trolley-problem cases.
Consequentialist moral judgments are more associated with rational thought than deontological judgment, but both deontological and consequentialist moral judgments have their sources in emotion. Deontological judgments are associated with 'alarm bell' emotions that circumvent reasoning and provide absolute demands on behavior. Alarm bell emotions are rooted in (for example) the amygdala. Consequentialist judgments are associated with 'currency' emotions provide negotiable motivations that weigh for and against particular behaviors, and are rooted in meso-limbic regions that track a stimulus' reward magnitude, reward probability, and expected value.
This chapter might be the best one in the book.
Chapter 3: Moral Motivation (Schroeder, Roskies, & Nichols)
The authors categorize philosophical theories of moral motivation into four groups:
- Instrumentalists think people are motivated when they form beliefs about how to satisfy pre-existing desires.
- Cognitivists think people are motivated merely by the belief that something is right or wrong.
- Sentimentalists think people are morally motivated only by emotions.
- Personalists think people are motivated by their character: their knowledge of good and bad, their wanting for good or bad, their emotions about good or bad, and their habits of responding to these three.
The authors then argue that the neuroscience of motivation fits best with the instrumentalist and personalist pictures of moral motivation, poses some problems for sentimentalists, and presents grave problems for cognitivists. The main weakness of the chapter is that its picture of the neuroscience of motivation is mostly drawn from a decade-old neuroscience textbook. As such, the chapter misses many new developments, especially the important discoveries occurring in neuroeconomics. Still, I can personally attest that the latest neuroscience still comes down most strongly in favor of instrumentalists and personalists, but there are recent details that could have been included in this chapter.
Chapter 4: Moral Emotions (Prinz & Nichols)
The authors survey studies that illuminate the role of emotions in moral cognition, and discuss several models that have been proposed, concluding that the evidence currently respects each of them. They then focus on a more detailed discussion of two emotions that are particularly causal in the moral judgments of Western society: anger and guilt.
The chapter is strong in example experiments, but a higher-level discussion of the role of emotions in moral judgment is provided by chapter 2.
Chapter 5: Altruism (Stich, Doris, & Roedder)
The authors distinguish four kinds of desires: (1) desires for pleasure and avoiding pain, (2) self-interested desires, (3) desires that are not self-interested and no for the well-being of others, and (4) desires for the well-being of others. Psychological hedonism maintains that all (terminal, as opposed to instrumental) desires are of type 1. Psychological egoism says that all desires are of type 2 (which includes type 1). Altruism claims that some desires fall into category 4. And if there are desires of tyep 3 but none of type 4, then both egoism and altruism are false.
The authors survey evolutionary arguments for and against altruism, but are not yet convinced by any of them.
Psychology, however, does support the existence of altruism, which seems to be "the product of an emotional response to another's distress." The authors survey the experimental evidence, especially the work of Batson. They conclude there is significant support for the existence of genuine human altruism. We are not motivated by selfishness alone.
Chapter 6: Moral Reasoning (Harman, Mason, & Sinnott-Armstrong)
The authors clarify the roles of conscious and unconscious moral reasoning, and reject one popular theory of moral reasoning: the deductive model. One of many reasons for their rejection of the deductive model is that it assumes we come to explicit moral conclusions by applying logic, probability theory, and decision theory to pre-existing moral principles, but in the deductive model these principles are understood in terms of psychological theories of concepts that are probably false. The authors survey the 'classical view of concepts' (concepts as defined in terms of necessary and sufficient conditions) and conclude that it is less likely to be true than alternate theories of mental concepts that are less friendly to the deductive model of moral reasoning.
The authors propose an alternate model of moral reasoning whereby one makes mutual adjustments to one's beliefs and plans and values in pursuit of what Rawls called 'reflective equilibrium.'
Chapter 7: Moral Intuitions (Sinnott-Armstrong, Young, & Cushman)
The authors refer to moral intuitions as "strong, stable, immediate moral beliefs." The 'immediate' part means that these moral beliefs do not arise through conscious reasoning; the subject is conscious only of the resulting moral belief.
Their project is this:
...moral intuitions are unreliable to the extent that morally irrelevant factors affect moral intuitions. When they are distorted by irrelevant factors, moral intuitions can be likened to mirages or seeing pink elephants while one is on LSD. Only when beliefs arise in more reputable ways do they have a fighting chance of being justified. Hence we need to know about the processes that produce moral intuitions before we can determine whether moral intuitions are justified.
Thus the chapter engages in something like Less Wrong-style 'dissolution to algorithm.'
A major weakness of this article is that it focuses on the understanding of intuitions as attribute substitution heuristics, but ignores the other two major sources of intuitive judgments: evolutionary psychology and unconscious associative learning.
Chapter 8: Linguistics and Moral Theory (Roedder & Harman)
This chapter examines the 'linguistic analogy' in moral psychology - the analogy between Chomsky's 'universal grammar' and what has been called 'universal moral grammar.' The authors don't have any strong conclusions, but instead suggest that this linguistic analogy may be a helpful framework for pursuing further research. They list five ways in particular the analogy is useful. This chapter can be skipped without missing much.
Chapter 9: Rules (Mallon & Nichols)
The authors survey the evidence that moral rules "are mentally represented and play a causal role in the production of judgment and behavior." This may be obvious, but it's nice to have the evidence collected somewhere.
Chapter 10: Responsibility (Knobe & Doris)
This chapter surveys the experimental studies that test people's attributions of moral responsibility. In short, people do not make such judgments according to invariant principles, as assumed by most of 20th century moral philosophy. (Moral philosophers have spent most of their time trying to find a set of principles that accounted for people's ordinary moral judgments, and showing that alternate sets of principles failed to capture people's ordinary moral judgments in particular circumstances.)
People adopt different moral criteria for judging different cases, even when they verbally endorse a simple set of abstract principles. This should not be surprising, as the same had already been shown to be true in linguistics and in non-moral judgment. The chapter surveys the variety of ways in which people adopt different moral criteria for different cases.
Chapter 11: Character (Merritt, Doris, & Harman)
This chapter surveys the evidence from situationist psychology, which undermines the 'robust character traits' view of human psychology upon which many varieties of virtue ethics depend.
Chapter 12: Well-Being (Tiberius & Plakias)
This chapter surveys competing concepts of 'well-being' in psychology, and provides reasons for using the 'life satisfaction' concept of well-being, especially in philosophy. The authors then discuss life satisfaction and normativity; for example the worry about the arbitrariness of factors that lead to human life satisfaction.
Chapter 13: Race and Racial Cognition (Kelly, Machery, & Mallon)
I didn't read this chapter.