The paper analyzes the relationship between adult siblings, their specificity and diversity, examples of relation typologies of adult siblings by American and Indian psychologists are adduced. The modern view of the attachment to the mother in adults and the conditions required for establishing close, trusting interpersonal relationships are briefly described. A succinct overview of modern foreign research in these fields of research is given. The national sample (N = 277) identified and described four types of relations between adult siblings: emotionally-positive (heart, harmonious) ones account 39 per cent of the sample; ambivalent (heart, conflictcompetitive ones account 32 per cent; debarred (not close, not conflict-competing) ones account 18 per cent; conflict (not close, competing conflict-up to hostile) ones account 11 per cent.

Comparison of the three typologies of adult sibling relationships (Russian, US and Indian). The intercouple comparison shows the reciprocity of sibling relationships in adulthood. The results of the empirical research reveal complex relationship features attachment to the mother with the nature of the relationship between siblings in adulthood. Thus there are adults with a reliable type of attachment to the mother with debarred or even conflicting relationships with older siblings, while adult sibling relationships are determined not totally emotional of the early relationship with the mother, and also depend on the sibling’s personality traits and personal history of relations. The influence of the attachment type to the mother is shaped in childhood and can be applied to the relationship between adult siblings.