Blackouts usually lead to baby boom
Predicting evenings and making night plans has become as predictable as the second coming of the Son of Man.
And just as certainly South Africa's maternity wards should brace for a post-power shedding boom in nine months' time.
The 1965 New York blackout and others worldwide set the scene.
South Africans have been bathed in darkness because Eskom does not have enough power-generating capacity, but others around the world experienced the same conditions decades ago. And their good citizens didn't waste their time.
The origin of the tale is generally traced to the New York blackout on November 9 1965. Nine months later and an army of expectant mothers descended on the city's hospitals.
South Africa's blackouts reached an unprecedented level in late December and picked up pace in January, a time when many babies are conceived even with the lights on.
Babalo Mathe, a psychologist, says conceptions are likely to increase during natural disasters or crises like blackouts.
"This is because people are confined to their homes for long periods. The disruption in routine caused by blackouts and the absence of television might contribute to the phenomenon."
He says that darkness leads people to embrace. We've seen it on Survivor and in informal settlements.
"Women usually need reassurance when it is dark. Men embrace them - then one thing usually leads to another."
Nadine Bloem, a sex therapist, agrees: "There are more kinds of sex than bonding sex. There's sympathy sex, reconciliation sex and, yes, reassurance sex."