Moral psychology is the study of human thought and behavior in ethical contexts. Historically, the term "moral psychology" was used relatively narrowly to refer to the study of moral development. This field of study is interdisciplinary between the application of philosophy and psychology. Moral psychology eventually came to refer more broadly to various topics at the intersection of ethics, psychology, and philosophy of mind. Some of the main topics of the field are moral judgment, moral reasoning, moral satisficing, moral sensitivity, moral responsibility, moral motivation, moral identity, moral action, moral development, moral diversity, moral character (especially as related to virtue ethics), altruism, psychological egoism, moral luck, moral forecasting, moral emotion, affective forecasting, and moral disagreement.
Today, moral psychology is a thriving area of research spanning many disciplines,Doris & Stich (2008), §1. with major bodies of research on the biological, cognitive/computational and cultural basis of moral judgment and behavior, and a growing body of research on moral judgment in the context of artificial intelligence.
History The origins of moral psychology can be traced back to early philosophical works, largely concerned with moral education, such as by Plato and Aristotle in Ancient Greece, as well as from the BuddhistGoodman, Charles, "Ethics in Indian and Tibetan Buddhism", The Stanford Encyclopedia of Philosophy (Summer 2021 Edition), Edward N. Zalta (ed.), URL = <https://plato.stanford.edu/archives/sum2021/entries/ethics-indian-buddhism/>. and Confucian traditions. Empirical studies of moral judgment go back at least as far as the 1890s with the work of Frank Chapman Sharp, coinciding with the development of psychology as a discipline separate from philosophy. Since at least 1894, philosophers and psychologists attempted to empirically evaluate the morality of an individual, especially attempting to distinguish adults from children in terms of their judgment. Unfortunately, these efforts failed because they "attempted to quantify how much morality an individual had—a notably contentious idea—rather than understand the individual's psychological representation of morality".
In most introductory psychology courses, students learn about moral psychology by studying the psychologist Lawrence Kohlberg, who proposed a highly influential theory of moral development, developed throughout the 1950s and 1960s. This theory was built on Piaget's observation that children develop intuitions about justice that they can later articulate. Kohlberg proposed six stages broken into three categories of moral reasoning that he believed to be universal to all people in all cultures. The increasing sophistication of justice-based reasoning was taken as a sign of development. Moral cognitive development, in turn, was assumed to be a necessary (but not sufficient) condition for moral action.
But researchers using the Kohlberg model found a gap between what people said was most moral and actions they took. In response, Augusto Blasi proposed his self-model that links ideas of moral judgment and action through moral commitment. Those with moral goals central to the self-concept are more likely to take moral action, as they feel a greater obligation to do so. Those who are motivated will attain a unique moral identity.
Following the independent publication of a pair of landmark papers in 2001 (respectively led by Jonathan Haidt and Joshua Greene), there was a surge in interest in moral psychology across a broad range of subfields of psychology, with interest shifting away from developmental processes towards greater emphasis on social, cognitive, affective and neural processes involved in moral judgment.
Methods
Philosophers, psychologists and researchers from other fields have created various methods for studying topics in moral psychology, with empirical studies dating back to at least the 1890s. The methods used in these studies include moral dilemmas such as the trolley problem, structured interviews and surveys as a means to study moral psychology and its development, as well as the use of economic games, neuroimaging, and studies of natural language use.
Interview techniques In 1963, Lawrence Kohlberg presented an approach to studying differences in moral judgment by modeling evaluative diversity as reflecting a series of developmental stages (à la Jean Piaget). Lawrence Kohlberg's stages of moral development are: Obedience and punishment orientation Self-interest orientation Interpersonal accord and conformity Authority and social-order maintaining orientation Social contract orientation Universal ethical principles
Stages 1 and 2 are combined into a single stage labeled "pre-conventional", and stages 5 and 6 are combined into a single stage labeled "post-conventional" for the same reason; psychologists can consistently categorize subjects into the resulting four stages using the "Moral Judgement Interview" which asks subjects why they endorse the answers they do to a standard set of moral dilemmas.
Survey instruments Between 1910 and 1930, in the United States and Europe, several morality tests were developed to classify subjects as either fit or unfit to make moral judgments. Test-takers would classify or rank standardized lists of personality traits, hypothetical actions, or pictures of hypothetical scenes. As early as 1926, catalogs of personality tests included sections specifically for morality tests, though critics persuasively argued that they merely measured intelligence or awareness of social expectations.
Meanwhile, Kohlberg inspired a new series of morality tests. The Defining Issues Test (dubbed "Neo-Kohlbergian" by its constituents) scores relative preference for post-conventional justifications, and the Moral Judgment Test scores consistency of one's preferred justifications. Both treat evaluative ability as similar to IQ (hence the single score), allowing categorization by high score vs. low score.
Among the more recently developed survey measures, the Moral Foundations Questionnaire is a widely used survey measure of the five moral intuitions proposed by Moral Foundations Theory: care/harm, fairness/cheating, loyalty/betrayal, authority/subversion, and sanctity/degradation. The questions ask respondents to rate various considerations in terms of how relevant they are to the respondent's moral judgments. The purpose of the questionnaire is to measure the degree to which people rely upon each of the five moral intuitions (which may coexist). The new and improved version of this instrument (i.e., Moral Foundations Questionnaire-2; MFQ-2) was developed in 2023. In this version, Fairness was split to Equality and Proportionality. Hence, the MFQ-2 measures Care, Equality, Proportionality, Loyalty, Authority, and Purity. In addition to survey instruments measuring endorsement of moral foundations, a number of other contemporary survey measures exist relating to other broad taxonomies of moral values, as well as more specific moral beliefs, or concerns.
Evolutionary origins
According to Haidt, the belief that morality is not innate was one of the few theoretical commitments uniting many of the prominent psychologists studying morality in the twentieth century (with some exceptions). A substantial amount of research in recent decades has focused on the evolutionary origins of various aspects of morality.
In Unto Others: the Evolution and Psychology of Unselfish Behavior (1998), Elliott Sober and David Sloan Wilson demonstrated that diverse moralities could evolve through group selection. In particular, they dismantled the idea that natural selection will favor a homogeneous population in which all creatures care only about their own personal welfare and/or behave only in ways which advance their own personal reproduction.
Tim Dean has advanced the more general claim that moral diversity would evolve through frequency-dependent selection because each moral approach is vulnerable to a different set of situations which threatened our ancestors.
Topics and theories
Moral identity
Moral identity refers to the importance of morality to a person's identity, typically construed as either a trait-like individual difference, or set of chronically accessible schemas. There are considered to be two main levels of perspective on moral identity. One of them the trait-based perspective theory where certain personality traits are triggered during moral situations. The second perspective is the socio-cognitive perspective where these moral identities are a "self-schema" that will occur due to the social environment. Moral identity is theorized to be one of the key motivational forces connecting moral reasoning to moral behavior, as suggested by a 2016 meta-analysis reporting that moral identity is positively (albeit only modestly) associated with moral behavior. Although moral identity mainly focuses on a moral action there is sometimes "moral disengagement" that will take place to reduce the negative consequences of an action or lack of action.
Moral satisficing The theory of moral satisficing applies the study of ecological rationality to moral behavior. In this view, much of moral behavior is based on social heuristics rather than traits, virtues, or utilitarian calculations. Social heuristics are a form of satisficing, a term coined by Nobel laureate Herbert Simon. Social heuristics are not good or bad, or beneficial or harmful, per se, but solely in relation to the environments in which they are used. For instance, an adolescent may commit a crime not because of an evil character or a utilitarian calculation but due to following the social heuristic "do what your peers do." After shifting to a different peer group, the same person's behavior may shift to a more socially desirable outcome – by relying on the very same heuristic. From this perspective, moral behavior is thus not simply a consequence of inner virtue or traits, but a function of both the mind and the environment, a view based on Simon's scissors analogy. Many other moral theories, in contrast, consider the mind alone, such as Kohlberg's state theory, identity theories, virtue theories, and willpower theories.
The ecological perspective has methodological implications for the study of morality: According to it, behavior needs to be studied in social groups and not only in individuals, in natural environments and not only in labs. Both principles are violated, for instance, by the study of how individuals respond to artificial trolley problems. The theory of moral satisficing also has implications for moral policy, implying that problematic behavior can be changed by changing the environment, not only the individual.
Darwin argued that one original function of morality was the coherence and coordination of groups. This suggests that social heuristics that generate coherence and coordination are also those that guide moral behavior. These social heuristics include imitate-your-peers, equality (divide a resource equally), and tit-for-tat (be kind first, then imitate your partner's behavior). In general, the social heuristics of individuals or institutions shape their moral fabric.
Moral satisficing explains two phenomena that pose a puzzle for virtue and trait theories: moral luck and systematic inconsistencies, as when teens who voluntarily made a virginity pledge were just as likely to have premarital sex as their peers who did not. From an ecological view of morality, such inconsistencies are to be expected when individuals move from one environment to another.