This article reviews the functions and negative consequences of two emotions that support reciprocal help in humans: compassion and gratitude. Compassion arises when an individual witnesses another individual’s suffering and can be distinguished from the experience-sharing of distress with that person. This emotion has a significant role in the caregiving response to vulnerable offspring and cooperative relations with non-kin. However, compassion may sacrifice the welfare of people who are not the target of this emotion or may hinder the target’s growth. Gratitude is generated when one benefits from someone else’s good intentions, and can be distinguished from a mere positive emotion or indebtedness. This emotion contributes to increasing the morality of the beneficiary and the benefactor and contributes to a high-quality relationship between them. However, gratitude may cause unnecessary harm to the beneficiary’s welfare. In an intimate relationship, unbalanced gratitude may decrease relationship satisfaction. Social emotions largely support reciprocal help in humans; however, these emotions evidently are not the sole requirement.

In adult attachment relationships, couples act as a safe haven and secure base with each other. Therefore, the attachment relation in adulthood is a mutual help relation. In this article, we review three topics related to attachment. First, the basic outline and measurement methods of adult attachment studies are discussed. The transfer and hierarchical structure of the attachment figure are also mentioned. Second, based on the model of “circle of security in adulthood,” the research on safe haven and secure base are outlined. Individual differences of these functions caused by attachment styles were also outlined. Third, the stage and reaction when attachment figure was lost, and the individual difference were discussed. A common and important point in these discussions is that the essence of the adult attachment relation is “felt security.”

Altruistic behaviors such as a helping may have a crucial role in stabilizing the survival of our species and social relationships. Spontaneous helping behavior is observed in humans, even in the early stages of development; however, it is rarely observed in other species. On account of the evolutionary background, our brain would be expected to have specific mechanisms underlying these behaviors. A considerable number of studies have tackled this issue by using noninvasive neuroimaging techniques such as functional magnetic resonance imaging (fMRI). In this paper, I review studies that have revealed the neural mechanisms underlying the motivation of helping others, as well as mentalizing functions. I also introduce the basic procedures of psychological experiments using fMRI. In the final part, I discuss advanced issues about the negative aspects of altruism such as excessive punishment or revenge to an unfaithful other and self-sacrifice.

Traditional psychology has primarily focused on the mechanism and development of human altruism. However, the functional significance and evolutionary origin of altruism are also important. The condition for altruism to evolve by natural selection is “positive assortment.” To guarantee positive assortment, variance within a group must be small, whereas variance between groups must be large, which results in “parochial altruism.” Some features of reasoning and memory in humans are believed to have been adapted to parochial altruism. However, humans sometimes show “generalized altruism” beyond each group they belong to. Clarifying the relationship between the function of the mind as a legacy of evolution and the structure of human social groups is important to understand altruism.

Although helping and cooperation are found in every culture, they are subject to many sociocultural influences. This review shows how cultures vary in the occurrence of prosocial behaviors, in the likelihood of asking and receiving help, and in the factors that promote or prevent helping. Independent and interdependent cultures differ in how much people offer help to ingroup members versus outgroup members, how much people seek help, and the relationship and self-worth concerns they have about receiving help. In this regard, differences also exist, depending on whether a particular culture follows a person-centric or a normative-contextual model of help. Future research should expand its scope by examining helping that does not involve apparent behaviors and that is invisible to the recipient. Future research should also consider the interchangeability of the provider and the recipient to better reflect the complexity of helping behaviors that seem more prevalent in interdependent cultures.