Is Race Genetic or Socially Constructed?

'How many different races are there? Pick a number, any number, says philosophy professor Philip Kitcher. Wherever there is an agenda there is a division to be made; race is a social construct with scientific levers. "If there’s one thing that we’ve learned from biological science and psychological science over the last century, it’s that there’s an enormous amount of variation within the groups that we’ve traditionally thought of as races, far more than there is between the groups we’ve traditionally thought of as races." This makes sense; historically, we've drawn the line wherever it has suited the mainstream agenda.  Philip Kitcher is the co-author of The Seasons Alter: How to Save Our Planet in Six Acts.' -- Big Think