There are, they note, a wide array of studies showing that social or professional advantage can be very strongly influenced by random factors that have no bearing on innate ability.
Names provide multiple examples. There are studies showing, for instance, that scientists whose surnames begin with letters early in the alphabet are more likely to win promotion. People who use their middle initials are more likely to be regarded as clever. People with easy-to-pronounce names are more likely to win positions than those with difficult ones. Men with posh surnames are more likely to end up as managers than factory fodder. And women with masculine-sounding first names who become lawyers are more likely to find preferment than those with girly ones.
And, of course, some types of randomness are so obviously influential that they are rarely remarked upon. Someone born in Boston, for instance, is far more likely to end up working for a Fortune 500 company than someone who happened to be born in Bangladesh.