What the Big Five Model Is
The Big Five model, also known as the Five Factor Model or FFM, is a framework that captures human personality along five broad dimensions. It consists of Extraversion, Agreeableness, Conscientiousness, Openness to Experience, and Neuroticism, and each of these factors is further subdivided into six narrower facets. The single most distinctive thing about the model is that it was not deduced from the hypotheses of any one theorist; it is a structure that emerged inductively out of an enormous body of empirical data. Decades of accumulated factor-analytic research have found the same five factors emerging again and again across many cultures and languages, and the model now functions as the de facto standard in personality psychology.
Historical Background and Development
The origins of the Big Five reach back to the lexical hypothesis of the 1930s. The starting point was the work of Gordon Allport and Henry Odbert, who extracted some 4,500 personality-describing words from an English dictionary. In the 1940s Raymond Cattell used factor analysis to reduce this vocabulary to 16 factors, and in the 1960s Ernest Tupes and Raymond Christal were the first to report a five-factor structure. Their finding attracted little attention at the time. It was in the 1980s, when Lewis Goldberg proposed the name "Big Five" and Paul Costa and Robert McCrae developed the standardised measure known as the NEO-PI-R, that research on the model expanded explosively. The contribution of Costa and McCrae was particularly substantial: by assigning six facets to each of the five factors, they made the description of personality considerably more fine-grained. From the 1990s onward, cross-cultural research advanced further, and the replicability of the five-factor structure has now been confirmed in more than 50 languages and cultural regions. That confirmation, however, rests on samples drawn largely from societies with widespread schooling and literacy, and studies in small-scale societies have reported that the five factors do not always reappear in the same shape. While that sampling bias remains, it is early to call the five a skeleton common to all of humanity.
Application to Compatibility Assessment
Splitting two personalities across the five factors is enough to narrow down which factor a vague sense of mismatch is coming from. Narrowing it down is where the model stops, however: whether that particular difference turns into an obstacle for the two people involved is not settled by the combination of factors alone. Similarity in agreeableness and in conscientiousness tends to accompany higher relationship satisfaction, whereas for extraversion similarity is not necessarily optimal. When both partners score high on neuroticism, conflict tends to increase; when only one partner scores high, the strain on the relationship becomes asymmetric. Similarity in openness promotes shared intellectual experience and contributes to the quality of a relationship over the long run. That said, Big Five scores alone cannot fully predict compatibility, and other factors such as attachment style and patterns of communication also have to be taken into account. What the model is good for is putting the overall shape of a personality into words along five axes; it is not good for announcing how a particular story ends. Differences between factors sketch a map of where the two of you are out of step, and how that gap is handled day to day lies outside the map. Before reading a set of scores as reassurance or as bad news, it is worth naming one concrete situation in which the difference actually shows up.
Measurement and Reliability
Several instruments exist for measuring the Big Five. The most comprehensive is Costa and McCrae's NEO-PI-R, with 240 items, which has demonstrated high reliability and validity for research purposes. Shorter measures include the NEO-FFI with 60 items, the BFI with 44 items, and the TIPI with only 10 items, and these are chosen according to the demands of the particular application. In Japanese, the adjective-based scale of Wada (1996) and the Big Five personality inventory of Murakami and Murakami (1999) are both in wide use. Self-report questionnaires are the dominant format, but agreement with ratings supplied by other people is also high, and correlations with behavioural observation data have likewise been confirmed. Test-retest reliability generally falls in the range of .70 to .90, which indicates that these instruments are measuring traits that remain comparatively stable across adulthood.