as a new father. that's what i heard for years. first two years are the years that matter the most because that's when the baby develops its personality . it stops crying and gets an attitude and maul dave brigs. >> no question about that. my son has a hot temper, i don't know where you got that. >> you are an grown two year old. >> you may have a point. you can start to see the personality traits at a year and two years. hot temper and physical . the new today points out that you develop your personality for life and the first, by first grade, you have developed the core identity. and then two years. journal social psychological and personality sids that is coming out. it is longer than two years. by first grade your personality is set it is a