Agreeableness
Agreeableness is the personality trait of being kind, sympathetic, cooperative, warm, honest, straightforward, and considerate. In personality psychology, agreeableness is one of the five major dimensions of personality structure, reflecting individual differences in cooperation. People who score high on measures of agreeableness are empathetic and self-sacrificing, while those with low agreeableness are prone to selfishness, insincerity, and zero-sum thinking. Those who score low on agreeableness may show dark triad tendencies, such as narcissistic, antisocial, and manipulative behavior.
Agreeableness is a superordinate trait, meaning it is a grouping of personality sub-traits that cluster together statistically. Some lower-level traits, or facets, that are commonly grouped under agreeableness include trust, straightforwardness, altruism, helpfulness, modesty, and tender-mindedness.
History
Early trait research
As is the case with all Big Five personality traits, the roots of the modern concept of agreeableness can be traced to a 1936 study by Gordon Allport and Henry S. Odbert. Seven years after that study, Raymond Cattell published a cluster analysis of the thousands of personality-related words identified by Allport and Odbert. The clusters identified in this study served as a foundation for Cattell's further attempts to identify fundamental, universal, human personality factors. Cattell eventually determined 16 personality factors by means of factor analysis. Further factor analyses revealed five higher-order, or "global", factors that encompass these 16. Although labelled "independence" by Cattell, one of the global factors identified by the 16PF Questionnaire was an early precursor to the modern concept of agreeableness.Big Five
Agreeableness in the five factor model of personality is most commonly measured by self-report, although peer-reports and third-party observation can also be used. Self-report measures are either lexical or based on statements. Which measure is used depends on and the time and space constraints of the research being undertaken.Lexical measures use individual adjectives that reflect agreeableness or disagreeableness traits, such as sympathetic, cooperative, warm, considerate, harsh, unkind, rude. Words representing disagreeableness are reverse coded. Goldberg developed a 20-word measure as part of his 100-word Big Five markers, and Saucier developed a briefer 8-word measure as part of his 40-word mini-markers. Thompson revised these markers to develop a 40-word measure with better psychometric properties in both American and non-American populations: the International English Mini-Markers. This brief measure has good internal consistency reliabilities and other validity for assessing agreeableness and other five factor personality dimensions, both within and, especially, without American populations. Internal consistency reliability of the agreeableness measure for native English-speakers is reported as.86, that for non-native English-speakers is.80.
Statement measures tend to comprise more words, and hence consume more research instrument space, than lexical measures. Respondents are asked the extent to which they, for example, on good terms with nearly everyone, not interested in other people's problems or ympathize with others' feelings.
Cattell's factor analytic approach, which aimed to identify, inspired many studies in the decades following the introduction of the 16PF. Using Cattell's original clusters, the 16PF, and original data, multiple researchers independently developed a five factor model of personality over this period. From the early 1960s on, these explorations typically included a factor called "agreeableness" or "sociability". Despite repeated replications of five stable personality factors following Cattell's pioneering work, this framework only began to dominate personality research in the early 1980s with the work of Lewis Goldberg. Using lexical studies similar to those of Allport and Odbert, Goldberg chose the term "Big Five" to reflect the sheer number of personality-related terms encompassed by each of these five distinct factors. One of these, agreeableness, was defined by a number of personality-related words similar to those present in earlier and more recent manifestations of the construct; examples include "friendly", "good-natured", "cooperative", "trustful", "nurturing", "sociable", and "considerate".
NEO PI
Beginning in the 1970s, Paul Costa and Robert McCrae began researching the development of personality assessments based on factor models. Beginning with cluster analyses of Cattell's 16PF, Costa and McCrae initially settled on a three-factor model of personality. These three factors were neuroticism, extraversion, and openness to experience, resulting in the acronym "NEO." Due to similarities between their three-factor NEO Personality Inventory and Goldberg's Big Five, Costa and McCrae began to develop scales to assess agreeableness and conscientiousness in the early 1980s. This work culminated in the 1985 publication of the first NEO PI Manual to be based on the full Five Factor Model. Although this marked the introduction of agreeableness to the NEO PI, Costa and McCrae worked for an additional seven years to identify and elaborate on the facets comprising this factor in the Revised NEO Personality Inventory.NEO PI facets
In the NEO PI, each of the five factors identified by Costa and McCrae are identified with six lower-level traits. Known as facets, the lower-level traits subsumed by agreeableness were first introduced with the 1992 publication of the revised version of the NEO PI. Based on the modern NEO PI-R, the six facets of agreeableness are: trust, straightforwardness, altruism, compliance, modesty, and tender-mindedness.Trust
Trust is viewed to be an important feature of psychosocial development, personality theory, and folk psychological conceptions of personality. Individuals who score high on trust generally believe others' intentions to be benevolent and can be naive if taken to the extreme. Those scoring low on this facet tend to be cynical and paranoid and view others as suspicious, dishonest, or dangerous.Straightforwardness
Straightforwardness is the quality of being direct, open, and honest in communicating with others. Despite a long history in moral philosophy, straightforwardness is not as vital to personality theory as the other facets of agreeableness. Those scoring high on straightforwardness tend to interact with others in a direct and honest manner. Low scorers are less direct, tend to be high in self-monitoring, are more reticent. Those who score low on this facet also tend to be high in Machiavellianism, being deceitful or manipulative with others. Straightforwardness is similar to a dimension in the Interpersonal circumplex called "ingenuous versus calculating." According to Michael C. Ashton and Kibeom Lee, straightforwardness is similar to the honesty aspect of honesty-humility in the HEXACO Model.Altruism
Similar to altruism in animals and ethical altruism, this facet is defined by measures of selflessness, self-sacrifice, generosity, and consideration, courtesy, and concern for others. Altruism is similar to Alfred Adler's concept of social interest, which is a tendency to direct one's actions toward the betterment of society. Individuals who score low on altruism tend to be discourteous, selfish, or greedy, a pattern of behaviors known as "self-interest" in Adlerian psychology.Compliance
As a facet of agreeableness, compliance is defined as an individual's typical response to conflict. Those who score high on compliance tend to be meek and mild, and to prefer cooperation or deference as a means of resolving conflict. Low scorers tend to be aggressive, antagonistic, competitive, quarrelsome, and vindictive.Modesty
While trust, straightforwardness, altruism, and compliance all refer to interpersonal or social behaviors, modesty refers to an individual's self-concept. Those who score high on modesty tend to be humble and other-focused, while low scorers tend to be arrogant, ostentatious, and self-aggrandizing. Low modesty is otherwise known as conceitedness or narcissism and, in extreme cases, can manifest as narcissistic personality disorder or histrionic personality disorder. Otherwise known as "humility" in the Revised NEO Personality Inventory, modesty resembles the humility aspect of honesty-humility in the HEXACO model.Tender-mindedness
Tender-mindedness is defined as the extent to which an individual's judgments and attitudes are determined by emotion. Coined by William James, this term was also prominent in early versions of the 16PF. Tender-mindedness is primarily defined by sympathy and corresponds to the International Personality Item Pool's "sympathy" scale. In contrast, "tough minded" is a trait associated with Psychoticism on the Eysenck Personality Questionnaire.Equivalents in psychobiological models
Models based on psychobiological theories of personality have each incorporated a factor similar to agreeableness. In Cloninger's Temperament and Character Inventory the character trait known as cooperativeness is very similar to and positively correlated with agreeableness. In Zuckerman's alternative five model of personality the trait known as aggression-hostility is inversely related to agreeableness.HEXACO model
To address the absence of measures of dark triad traits, Michael Ashton and Kibeom Lee proposed the addition of a sixth factor to the five factor model. Validated with psycholexical studies similar to those used in the development of the five factor model, the HEXACO model adds honesty-humility to five factors resembling those in the NEO PI. Although honesty-humility does not directly correspond to any Big Five trait, it is strongly correlated with the straightforwardness and modesty facets of Big Five agreeableness. As both of these facets are only weakly correlated with Big Five agreeableness, Ashton and Lee suggest dividing NEO PI agreeableness into two factors similar to those in the HEXACO model: honesty-humility and a redefined agreeableness. Reflecting this conception of honesty-humility and HEXACO agreeableness as unique though similar concepts, Ashton and Lee propose that they represent different aspects of reciprocal altruism: fairness and tolerance.Despite suggesting this reconceptualization of agreeableness for the NEO PI, Ashton and Lee do not believe HEXACO agreeableness is accurately captured by trust, altruism, compliance, and tender-mindedness. In addition to accounting for these four facets of Big Five agreeableness, the HEXACO model's construction of agreeableness includes content categorized under neuroticism in the NEO PI. To reflect the negative emotional content at the low end of HEXACO agreeableness, this factor is also referred to as "agreeableness." The inclusion of anger in the definition of HEXACO agreeableness further helps to differentiate this factor from honesty-humility. In response to offensive or transgressive actions, individuals who score low on honesty-humility tend not to respond immediately. Instead, they defer their response by planning their revenge and waiting for the perfect opportunity to enact it. Although those who score low on HEXACO agreeableness also employ this premeditated strategy, they also tend to respond immediately with anger.