His ideas about childcare influenced several generations of parents to be more flexible and affectionate with their children, and to treat them as individuals. However, they were also widely criticized by colleagues for relying too heavily on anecdotal evidence rather than serious academic research.[2] In addition to his pediatric work, Spock was an activist in the New Left and anti Vietnam War movements during the 1960s and early 1970s. At the time his books were criticized by Vietnam War supporters for allegedly propagating permissiveness and an expectation of instant gratification that led young people to join these movements, a charge Spock denied.