The work deals with the principle of sympathy as one of the effective influent instruments on the individual, which is widely used in advertisments, trade interpersonal relationships. It is shown that people prefer to agree to people, who are well known to them and due to some reasons are sympathetic to them, regularities of the influence of sympathy upon people's decisions, connected with the expression of compliance is considered as the manifistation of the regularity of the consistency of attitudes.