Sentence:  <WSD>Troglodytism</WSD> does not necessarily imply a low cultural level. The picture of the caveman dragging his mate by her hair is a cartoonist's cliché, betraying nostalgia for bygone days, rather than a portrait of the kind of people who prefer to live below ground. 
Meaning of the word marked with <WSD> tags:  The practice of living in caves or cavelike environments.