It likely was never actually a safe practice for females, but was a highly popular means of transport for girls in the hippy era. By the late sixties, it started to be recognized as a not-so-healthy exercise for ladies. Below are a couple articles which highlight the growing awareness that this fad may not be the best idea ever. Also presented are some images of female hitch-hiker ephemera from the period…. The full pages are below. Who are the participants in this now fashionably popular, high-risk sport?
The forgotten art of hitchhiking — and why it disappeared
Exploring your genome
We will be able to determine our phenotype for all the traits. We will try to figure out our genotype if possible as well. Straighten your thumb. Straight thumbs are homozygous recessive hh. Check your thumb and record your phenotype in a chart. People homozygous recessive dd do not have dimples.
Hitchhiking also known as thumbing or hitching is a means of transportation that is gained by asking individuals, usually strangers, for a ride in their car or other vehicle. The ride is usually, but not always, free. Nomads have also used hitchhiking as a primary mode of travel for the better part of the last century, and continue to do so today. Hitchhikers use a variety of signals to indicate they need a ride.
A thumb signal , usually described as a thumbs-up or thumbs-down , is a common hand gesture achieved by a closed fist held with the thumb extended upward or downward in approval or disapproval, respectively. These gestures have become metaphors in English: "The audience gave the movie the thumbs-up" means that the audience approved of the movie , regardless of whether the gesture was actually made. While the exact source of the thumb gesture is obscure, a number of origins have been proposed. Carleton S. Coon , having observed Barbary apes in Gibraltar using the gesture, hypothesised in the anthropological classic The Story of Man that it is a mutual celebration of having opposable thumbs.