“…The properties that match in identical twins are being attributed more closely to genes than the properties that match both identical and non-identical twins ( Tan et al., 2015 ). Thus, identical and non-identical twins enable scientists to understand the influence of genes and the environment on the personality and developmental characteristics of the individual ( Matthews et al., 2010 ), for example on the nature of learning needs ( Clay, 1989 ; Preedy, 1999 ), development of mental, verbal and non-verbal skills ( Asbury et al., 2005 ; Thorpe, 2006 ), social skills ( Cherro 1992 ), exercising abilities ( Stubbe et al., 2006 ), identity ( Ainslie, 1997 ; Klein, 2012 ), creativity ( Velázquez et al., 2015 ) and individuality ( Nobel et al., 2017 ).…”