That the concept concerned is a misnomer can be gleaned even from the very circumstances of its birth alone.

Although its origins are claimed to go back to classic authors such as Adam Smith and Montesquieu (Sturgess 1997, Woolcock 1998, Schuller et al. 2000), it was an otherwise obscure writer going under the name of Lyda J. Hanifan who introduced the term into use in “The Community Center”, published in Boston in 1920:

In the use of the phrase social capital I make no reference to the usual [understanding] of the term capital, except in a figurative sense. I do not refer to real estate, or to personal property or to cold cash, but rather to that in life which tends to make these tangible substances count for most in the daily lives of people, nameły goodwill, fellowship, mutual sympathy and social intercourse.... (Hanifan 1916)

The reader’s attention may be drawn to the aforementioned author’s awareness of metaphorical nature of the concept in question, which has been somewhere along the way lost is by its subsequent users.