Consumers' personalities also influence their buying decisions and attitudes to the brand. Additionally, a customer's personality relates to self-concept. This refers to "the totality of person's thought and feelings with reference to himself/herself as the object" (Kim, Han & Park 2001, p. 198). The self-concept consists of a set of self-perceptions that are reasonably stable but changeable. These perceptions are developed through social interaction. It can simply mean that the self-concept has impact on a consumer's behaviour. The individual's self-concept plays a role in choosing certain products. Thus, a customer's self-concept has a tendency to develop a preference to particular brand which he/she feels the match their self-image; In other words they search for products that provide a means of self-expression. In addition, the study found that the interaction of a buyer's personality and the image of the purchased product often influenced the consumer's buying behaviour. However, many consumers choose products rationally on the basis of comparing quality of products, price shape, color and packaging that directly appeal to the consumer's emotions (Kim, Han & Park 2001).
Similarly, (Pitta & Katsanis 1995, p. 53) stated that "brand personality reflects how people feel about a brand, rather than they think the brand is or does". Brand personality is one of the core dimensions of brand equity. Brand personality refers to the emotional side of brand image. It is created by a customer's experience with a brand. Thus, most marketers use a consumer's personality as a tool to create a brand and advertising. This is because a customer's characteristics influence their buying behaviour. For example, the brand character of M&M is laugh and joke (Pitta & Katsanis 1995).
One way to conceptualize and measure human personality is the trait approach, which states that personality is a set of traits. Human personality determined by multi-dimensional factors like individual's behaviour, appearance, attitude, and belief, and demographic characteristic.