Background. Team sports are not only the most exciting sporting events. but also complex activities that make serious demands on players. The effectiveness of the team depends not only on the high level of gaming interaction. but also on the relationship between the players. The work is based on the material of sports teams and is devoted to the study of the phenomenon of group cohesion. As a basic model. the authors choose a 4-factor model that describes cohesion in sports teams. The paper also considered the phenomenon of the emergence of the aggregate subject in the process of joint activity. when the participants feel themselves as a whole and experience feelings of satisfaction and a surge of energy. 

Objective. The main objective of the work is to investigate the relationship between the level of team cohesion and subjective feelings of unity of its players. As additional variables in the study there is a sport (football and volleyball) and team level (amateur and professional). 

To test the assumptions. two methods were used (the Sport Team Cohesion Questionnaire and the Subject Unity Index). which allow not only to determine the overall level of cohesion and unity. but also to reveal the structure of both phenomena. The study involved two men’s volleyball and two men’s football teams of different ages: 8-9 years (39 athletes); 12-14 years (24 athletes) and 18-25 years (41 athletes). 

Design. For amateur groups represented by children’s and teenage sports teams. significant correlations between unity and unity were obtained (r = 0.618. p <0.01; r = 0.477. p <0.05). For professional teams. no significant correlations were found. Influence of the sport on cohesion is also different for amateur and professional teams. In the first case. the cohesion is higher for football players (U = 118. p <0.05). and in the second case for volleyball players (U = 124. p <0.05). 

Results. The findings indicate that the professional level of players affects group cohesion and the phenomenon of group unity. The authors explain this by the fact that for professionals the main motive of the activity is to receive a reward for the game. and for the amateurs - the pleasure from joint actions.