Affection or fondness is a "disposition or state of mind or body" commonly linked to a feeling or type of love. It has led to multiple branches in philosophy and psychology that discuss emotion, disease, influence, and state of being. Often, "affection" denotes more than mere goodwill or friendship. Writers on ethics generally use the word to refer to distinct states of feeling, both lasting and temporary. Some contrast it with passion as being free from the distinctively sensual element.
Affection can elicit diverse emotional reactions such as embarrassment, disgust, pleasure, and annoyance. The emotional and physical effect of affection also varies between the giver and the receiver.
More specifically, the word has been restricted to emotional states, the object of which is a living thing such as a human or animal. Affection is compared with passion, from the Greek word pathos. As such, it appears in the writings of French philosopher René Descartes, Dutch philosopher Baruch Spinoza, and most of the writings of early British ethicists. However, on various grounds, it is generally distinguished from passion. Some definitions of affection do not involve anxiety or excitement, which is considered to be a part of passion. In this narrower sense, the word has a role in ethical systems, which relate to the social or parental affections, a part of moral obligations, or of affection as a virtue. Ethical systems may depend on whether affection is considered voluntarily.
Affection can be communicated by looks, words, gestures, or touches. It conveys love and social connection. The five love languages explains how couples can communicate affections to each other. Affectionate behavior may have evolved from parental nurturing behavior due to its associations with hormonal rewards. Such affection has been shown to influence brain development in infants, especially their biochemical systems and prefrontal development.
Expressions of affection can be unwelcome if they pose implied threats to one's well-being.