‘Smart People’ at Writers: A skilled playwright stirs foursome into existential comedy on race

Review: The smartest thing about Lydia R. Diamond’s play “Smart People,” now installed at Writers Theatre, may be the playwright herself. Diamond has a slashing wit and a ringing command of language. Whether “Smart People” adds up to all that much, or indeed whether it’s as fresh and imaginative as its high energy suggests, are other matters. ★★★