That would seem to be the implication of the part of his discussion of the loss of "social capital" that deals with the increase in the percentage of women in the labor force. He tells readers:
"Work: The main trend was the gradual entrance of millions of women into the job market. In 2015, 74 percent of prime-working-age women (25 to 54) were in the labor force, up from 35 percent in 1948. However, there were social costs. There was more 'reliance on markets for child care,' and 'community-based' volunteer work suffered. Meanwhile, increasing numbers of men with lower levels of education dropped out of the labor force."
It is not clear what exactly Samuelson means here, but presumably he is mentioning the decline in the labor force participation rate of less-educated men as one of the "social costs" of women entering the labor market. If so, the linkage is more than a bit bizarre. Countries like Sweden, Denmark, and Japan all had large increases in women's labor force participation rates without any large decline in participation rates for men.
There are certainly economic and social factors that have reduced employment opportunities for less-educated men (mass incarceration is a big one), but it is a stretch to blame this on women entering the labor force.