Some, but the catch is when it starts. The big representative series all begin after the Pill (FDA 1960), so they can't see the "before" side.
- General Social Survey (US): asked married people "how would you describe your marriage?" from 1973. "Very happy": 67.8% in 1973, 61.4% in 2010, 59.4% in 2024 (GSS cumulative file).
- Same survey, sex frequency since 1989: adults had sex about 9 fewer times a year in 2010-14 than in 1995-99, mostly because fewer people had a steady partner (Twenge, Sherman & Wells 2017, Archives of Sexual Behavior, doi:10.1007/s10508-017-0953-1).
- First nationally representative sex surveys: US NHSLS in 1992 (Laumann), Britain's Natsal in 1990-91. Kinsey (1940s-50s) wasn't a random sample.
So for courtship-era heartbreak and distress you're left with letters, diaries, court and suicide records, which don't give comparable population rates. Anyone claiming a hard number for 1900 vs today is guessing.
