Encyclopedia of Evolutionary Psychological Science

Living Edition
| Editors: Todd K. Shackelford, Viviana A. Weekes-Shackelford

Theory of Moral Development

  • Onurcan YilmazEmail author
  • Hasan G. Bahçekapili
  • Barış Sevi
Living reference work entry
DOI: https://doi.org/10.1007/978-3-319-16999-6_171-1



Kohlberg’s theory of moral development explains how moral development takes place in human animals.


The nature and the cognitive and emotional determinants of moral judgment have been empirically studied since the emergence of the science of psychology. Although one of the first systematic theories began with Piaget (1965), the first systematic theory based on empirical research was introduced by Lawrence Kohlberg (1969). Kohlberg’s theory is regarded as a rationalist theory since it assumes that the main determinant of moral judgment is rational thinking processes, even though it is thought that emotional or intuitive processes are also involved – at least in part – in moral judgment.

Kohlberg’s Three Levels

There are three levels (in a total of six stages) in Kohlberg’s theory of moral development in a hierarchical structure. These three levels follow a stable sequence but qualitatively correspond to different types of moral reasoning. The first and primary motivation of the first level (pre-conventional morality), which includes the first two stages (obedience and punishment; individual interests), is to avoid punishment and attain pleasure. The individual at the first stage does not understand or care that other people can have similar wishes and desires besides their own desires. Thus, the person in this stage acts in an egoist manner. Then, in the second stage, the person realizes that she can differentiate her own desires from the wishes of other people and the authority figures. At the second level (conventional morality), which includes the third and fourth stages (interpersonal; authority), the individual has a motivation that is concerned with mutual relations and expectations. The main motivation of the individuals at this level is to be accepted and socially approved by others and, in this context, to fulfill the orders of those who are hierarchically superior. Therefore, at this level, people define interpersonal relations through their place in society. At the last and third level (the post-conventional morality), the individual develops an autonomous moral conception, while in moral judgment she often refers to a universal set of principles (such as justice and fairness). This stage corresponds to a universal set of moral principles that all people must follow, according to Kohlberg, and moral superiority is characterized as reaching this stage. The normative moral superiority, which a rational human being as in Kant’s categorical imperative must achieve as a result of cognitive reasoning, is a sense of universal justice. The individual in this stage sees morality as an end, not as a means.

Assessing Morality

Kohlberg scores people’s moral judgments based on how they justify their moral judgments in terms of these three levels (i.e., pre-conventional, conventional, and post-conventional moralities). For example, in the well-known Heinz dilemma, the participant reads the following moral vignette:

A woman was on her deathbed. There was one drug that the doctors thought might save her. It was a form of radium that a druggist in the same town had recently discovered. The drug was expensive to make, but the druggist was charging ten times what the drug cost him to produce. He paid $200 for the radium and charged $2,000 for a small dose of the drug. The sick woman’s husband, Heinz, went to everyone he knew to borrow the money, but he could only get together about $1,000 which is half of what it cost. He told the druggist that his wife was dying and asked him to sell it cheaper or let him pay later. But the druggist said: “No, I discovered the drug and I’m going to make money from it.” So Heinz got desperate and broke into the man’s laboratory to steal the drug for his wife. Should Heinz have broken into the laboratory to steal the drug for his wife? Why or why not?

According to Kohlberg, the decision of the participant regarding whether Heinz should or should not steal the drug has no theoretical significance. However, it is theoretically important as to how the participant justifies her moral judgment. Someone who says that Heinz should not steal the drug, because if he steals, he must be imprisoned (i.e., avoiding punishment), or Heinz should steal because if his wife lives he will make Heinz a happier person (self-interest) is scored as having pre-conventional morality. Someone who states that Heinz should not steal the drug because the legal rules prohibit it or that Heinz should steal the drug because his wife would expect him to be a good husband is scored as having conventional morality. Someone who says Heinz should steal the drug because everyone has the right to live or Heinz should not take the drug because others may need this medicine and everyone’s life is equally important (i.e., universal human rights) is scored as having post-conventional morality.

According to Kohlberg (1971), moral development does not progress only with age (i.e., biological maturity); however, moral reasoning should be related to cognitive reasoning capacity. It has been found that the individuals who scored as having post-conventional morality showed higher performance in some tasks measuring cognitive reasoning (Kuhn et al. 1977). However, the theory of Kohlberg’s moral development was later criticized by different theoretical perspectives (cf., Haidt 2001). It is thought that empathy capacity, rather than cognitive development (e.g., Hoffman 1993), may be an important factor in determining moral reasoning. However, Kohlberg (1981) actually believes that the ability to take perspective, a cognitive capacity, is the fundamental determinant of moral reasoning.

Criticisms of Kohlberg’s Theory

The theory of Kohlberg’s (1969) moral development has been subjected to a number of criticisms from both theoretical and methodological perspectives. The most important theoretical criticism is the claim of universality of the hierarchical structure proposed by the theory. However, Turiel et al. (1978) showed that the basic assumptions of the theory were supported in a cross-sectional study. Likewise, Nisan and Kohlberg (1982) and then Colby et al. (1983) tested Kohlberg’s theory and showed that most of the predictions were supported in a longitudinal design as well. But all of these studies have some certain limitations, such as being based on hypothetical dilemmas to measure moral judgment (see below).

In addition, the argument that rational processes are the main determinant of moral judgment has been criticized (Haidt 2001). In fact, there are two theoretical perspectives on the study of cognitive processes of moral judgment. The first is the Kantian theory, which Kohlberg adopted, which assumes that rational processes are more active than affective processes when making a moral judgment. In this theoretical approach, although emotional forces are – at least in part – involved, the main determinant of moral judgment is essentially rational. So Kohlberg thinks that the goal of a layperson in making a moral judgment is to reach the normatively superior moral principle like a truth-seeking scientist who always tries to find the universal principles of nature. According to this approach, someone with sufficient cognitive reasoning ability is more likely to score on higher levels of morality. The second theoretical approach to the psychological origins of moral judgment is the Humean sentimentalist approach (Haidt 2001). According to this approach, we use our intuitive rather than our rational processes when making a moral judgment. Accordingly, when an event occurs, strong emotions such as disgust or anger emerge that lead us to intuitively conclude that the situation is morally right or wrong. After the moral judgment, we use our rational processes only for justification of the previous, already made moral judgment. To test this sentimentalist approach of Hume, the Julie and Mark scenario, which is well known in the literature, is used. In this scenario, the participants read the following scenario:

Julie and Mark are brother and sister. They are traveling together in France on summer vacation from college. One night they are staying alone in a cabin near the beach. They decide that it would be interesting and fun if they tried making love. At the very least, it would be a new experience for each of them. Julie was already taking birth control pills, but Mark uses a condom too, just to be safe. They both enjoy making love, but they decide never to do it again. They keep that night as a special secret, which makes them feel even closer to each other. What do you think about that? Was it ok for them to make love?

Although this scenario is defined as a harmless taboo violation (i.e., there is no direct harm behavior in this scenario; but see Royzman et al. 2015 for a counterargument), the majority of respondents automatically describe the incest behavior in the scenario (in which the feeling of disgust is activated) is morally wrong, and, in doing so, they use their intuitive and low-effort thinking styles (Haidt 2001). Only when they are asked why, do they seek to justify their judgment by using their analytic (high-effortful) thinking processes. Overall, Hume’s alternative (sentimentalist) theoretical framework, therefore, claims that we, as a lawyer, try to justify our moral decisions rather than to seek the truth, as do scientists when making moral judgments. This is a direct critique of Kohlberg’s rationalist view of moral judgment.

Another theoretical criticism is that the moral judgments scored as conventional level always correspond to traditional and conservative values, whereas those judgments scored as post-conventional level are mostly related to liberal values of justice and universalism. Haidt (2012) argues that this hierarchical approach is a natural result of the age of Enlightenment and thus is biased toward Western thinking style. However, according to Haidt and Kesebir (2010), this hierarchical approach suggested by Kohlberg is simply wrong, because almost every moral principle that Kohlberg proposed has an evolutionary background and is present in every human being. However, the conservative moral values, scored as conventional level, are suppressed by political liberals (and the majority of Western people) by spending cognitive effort, and as a result, they perceive those foundations as morally irrelevant. However, when we look at the rest of the world (i.e., non-WEIRD cultures: Western, educated, industrialized, rich, and democratic cultures; Henrich et al. 2010), those who value universal principles of justice and fairness (i.e., post-conventional morality) constitute only a small minority (see also Shweder et al. 1997). Hence, the theory’s view of liberal values as the top and hierarchically superior level of morality is substantially criticized, and it is thought that Kohlberg’s theory of moral development is developed in a way that has a direct Western cultural bias. Apart from that, this hierarchical structure is criticized on its own. Rest (1979), for example, claims that some participants were moving backward in stages. However, since Kohlberg considers the development of cognitive development as related to moral development, he claims that the more the cognitive development increases, the greater the moral development.

Another criticism is related to alleged gender bias embedded in Kohlberg’s theory of moral development. In the studies of Kohlberg, men generally score higher than women. However, Gilligan (1977) attributed this to the fact that the theory is constantly tested on male samples and that the higher levels are formed by principles such as justice that men value more. In fact, women often focus more on harm principles than on justice, but justice is considered as a higher moral principle in Kohlberg’s classification.

In addition to this male-female discussion in terms of Kohlberg’s theory of moral development, this can be seen as a methodological limitation as well since Kohlberg often conducted research with male participants. More importantly, however, Kohlberg sought to observe age-related changes using cross-sectional designs. In other words, one-to-one interviews with children of different ages were conducted to understand what kind of differences there were between different ages instead of conducting longitudinal studies with the same participants. Although later Colby et al. (1983) conducted a 27-year longitudinal study showing that Kohlberg’s theoretical approach is supported, there is still some controversy today regarding the validity of the methods used by Kohlberg.

In addition, some limitations of the method he used were later reported. For example, the moral dilemmas that are used are very artificial, which in turn might lead to a serious problem for ecological validity. Rosen (1980) reports that many of the dilemmas used by Kohlberg are very artificial. For example, the Heinz dilemma is very artificial for the children in the sense that the majority of the participants of Kohlberg range between 10 and 17 years of age, who have not been married and have never had a similar dilemma in their lives before. A second limitation of the scenarios used is the use of completely hypothetical scenarios. However, it is known that there can be discrepancies between hypothetical decision-making and real-life behavior, and the participants can sometimes report on the hypothetical scenarios that they will do things that people will not do in real life (Bostyn et al. 2018).


Kohlberg’s theory of moral development can be considered as one of the first systematic – and empirically testable – theoretical approaches trying to understand the developmental stages of moral judgment, which is based on Piaget’s moral theory. However, as outlined above, this approach is subject to substantial criticism from both the theoretical and the methodological perspectives and gives way to alternative theoretical approaches such as the moral foundations theory (Haidt 2012) and morality as cooperation theory (Curry et al. 2019). However, it is important to note that it maintains its claim to be the richest theoretical approach to date to explain especially how morality develops, which is lacking in the contemporary alternative theoretical approaches. In this respect, alternative theoretical approaches that emphasize the developmental sequences of moral judgment are needed in the field of moral development.



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Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Onurcan Yilmaz
    • 1
    Email author
  • Hasan G. Bahçekapili
    • 2
  • Barış Sevi
    • 3
  1. 1.Kadir Has UniversityIstanbulTurkey
  2. 2.Dogus UniversityIstanbulTurkey
  3. 3.Department of PsychologyWest Virginia UniversityMorgantownUSA

Section editors and affiliations

  • Tara DeLecce
    • 1
  1. 1.Department of PsychologyOakland UniversityRochesterUSA