In “Reciprocity and the Welfare State,” Christina Fong, Samuel Bowles, and Herbert Gintis (2005) cite Friedrich Hayek on the relation between the ancestral band and the welfare state, but they completely omit any engagement of Hayek’s criticism of the social-democratic welfare state as atavistic. That moment in their work epitomizes something occurring in a major new line of literature. In the last thirty years there has been a boom in works exploring the origin of human cooperation and morality. Many works of that literature, from Elliott Sober and David Sloan Wilson’s Unto Others to Bowles and Gintis’s A Cooperative Species to Christopher Boehm’s Moral Origins, explain cooperation and morality by drawing on the principle of sympathy that Adam Smith explored in The Theory of Moral Sentiments. Fong, Bowles, and Gintis (2005) argue that the welfare state has benefited from our sympathetic instincts, and that good welfare policies must take advantage of those instincts. This general argument about the nature of the welfare state is not unique. Frans de Waal has made similar arguments in his The Age of Empathy. In this paper, I elaborate on Smith’s insights about moral sentiments and argue that they dovetail with Hayek’s criticism of large-scale welfare statism. Thus, Smith does not provide a good basis for the evolutionary left. Although our social instincts do desire cooperation encompassing all of society, such cooperation is impossible today because of the complex nature of modern society. The desire for a welfare state supported by our social instincts is therefore atavistic, as Hayek argued in The Fatal Conceit, and originates from a desire for a society simpler than the one people live in today. In the present article I develop ideas from Smith and Hayek to insist that those who explore connections between the band ancestry of sympathy and solidarity and the modern appeal and politics of the welfare state must face up to and engage the classical liberal contention that the latter is atavistic.