They give details of inequality in education and learning; work, income and the economy; health and care; justice, security and the right to life; and the individual and society.
I started by looking at the references, and they mostly relate to government reports, trade union reports, a Guardian article and some books and working papers. There was nothing I could find from the peer-reviewed literature on scholastic attainment or intelligence, and nothing on genetics or the heritability of behavioural characteristics. This is a prime example of a confection which is lawyerly rather than scholarly. It is written by lawyers who ignore the world-as-it-is for the world-as-they-want-it-to-be; nay, the world as they command it to be.