It may be no coincidence that these elements are both「emphasis on hand」and「emphasis on cliff」: early hominids dwelt under overhanging cliffs that often formed shallow caves, and, the English word 'man' actually means 'hand' (from the Latin manu as in 'manual, maneuver, manipulate' and so on).
　Many concepts depicted in glyphs originated with the earliest of humans, the so-called 'cave people, caveman, cavewoman' because they intelligently chose to dwell in ready-made, sturdy housing units that were easily defendable, with a naturally climate-controlled temperature year-round, and were not vulnerable to most weather catastrophes.
　Anthropologists explain that what separated humans from other primates was the use of an opposable thumb for grasping (that is to say, also for keeping in touch with oneself…) with「emphasis on the hand.」Frankly, early humans resembled some other great ape primates, such as our closest genetic relative the bonobo, in many ways even more so than today. For example, elements may also be「palming of erection」(or,「emphasis」on「hand」) that describes a CAVEMAN, MAN CAVE, and「control of erection」in the CAVE O' WONDERS operated by religious shamans and cavewomen proprietresses (see 廣)
　「Evolutionary biologists have traced the origins of masturbation to ancient primates that predate the first humans by tens of millions of years. The findings emerged from what scientists believe is the largest dataset ever compiled on the activity, and confirm that humans arose on a branch of the tree of life replete with self-pleasuring predecessors. 'What we can say is this behaviour was present around 40m (40,000,000) years ago, in the common ancestor of all monkeys and apes,' said Dr Matilda Brindle, the lead researcher on the study at University College London. 'It's not that some species woke up one day and started doing it. This is an ancient, evolved trait. …This is such a common behaviour across the animal kingdom, I find it absolutely baffling that nobody has researched it before,' said Brindle. 'For people who think masturbation is wrong, or unnatural in some way, this is perfectly natural behaviour. It's part of our healthy repertoire of sexual behaviours.'」
　　[　https://www.theguardian.com/science/2023/jun/07/origins-masturbation-traced-back-primates-40m-years-ago　]　
　「Like humans…bonobos separate sex from reproduction. They seem to treat sex as a pleasurable activity, and they rely on it as a sort of social glue, to make or break all sorts of relationships. 'Ancestral humans behaved like this,' proposes Frans de Waal, an ethologist at the Yerkes Regional Primate Research Center at Emory University. 'Later, when we developed the family system, the use of sex for this sort of purpose became more limited, mainly occurring within families [i.e., incest]. A lot of the things we see, like pedophilia and homosexuality, may be leftovers that some now consider unacceptable in our particular society.' 」
　　[　https://www.discovermagazine.com/mind/casual-sex-play-common-among-bonobos 2023-05-14　]　
　「The bonobo, an African ape closely related to humans, has an even bigger sexual appetite. Studies suggest 75 percent of bonobo sex is nonreproductive and that nearly all bonobos are bisexual.」
　　[　https://www.mentalfloss.com/posts/weird-animal-sex-facts 2023-05-44　]　
　Element meaning CAVERNOUS,「cliff」with a marker on the top to denote a wide rock ceiling straight up from within a cavern.「Cliff」sometimes includes「repeatedly bobbing head」as the horizontal stroke, and the cave folks may have needed to repeatedly bow their heads while entering a low opening into a cave. Many ancient Chinese human dwelling sites are formed from sandstone eroded from beneath, and millions of Chinese still live in caves today, called yaodongs.
　Elements as「head erect」suggest Homo erectus, an extinct species of hominid that lived throughout most of the Pleistocene geological epoch, standing inside a covered area such as a cave.
　Regarding bonobos, the animal species with 98.7% of DNA exactly identical to that of human beings:
　「Female dominance is established first by seniority and then by affiliation to the senior female. Female bonobos constantly engage in tribidation, genital-on-genital contact. This sexual activity appears to be a means of reinforcing social bonds and of climbing the social ladder. (Dominant females were found to engage in these activities least frequently, indicating the stability of their status and the desirability of sexual exchanges with them.) Females leave their family groups as they mature, forcing them to court the affections of the dominant females of the new groups they hope to join.」
　「Lest you think that homosexual exchanges are exclusively sapphic [i.e., female homosexuality], male bonobos frequently engage in mutual masturbation for a variety of social reasons as well. Interestingly, bonobos are the only species aside from humans that engage in face-to-face intercourse and tongue kissing.」
　「This constant sexual activity of bonobos may account for another major difference between chimp and bonobo societies. Reproductive behavior in chimps can turn into a violent affair. Females are often taken by force sexually, and young offspring may be killed by males competing for sexual dominance. Mating is allowed according to male hierarchy. Subordinate males are violently discouraged from obtaining sexual access to females. Bonobo females, however, are approached respectfully by prospective partners and males abide by their refusals. Infanticide has never been recorded in the species.」
　「This startling difference can be accounted for by the fact that female chimps are sexually receptive during only a short period of their cycle, meaning that sexual encounters with them are at a premium. Female bonobos constantly mate, regardless of where they are in their cycle. This has the added advantage of making paternity impossible to determine and thus making violence against their offspring unlikely. Why would a male bonobo kill a juvenile who might be his son or daughter?」
　「It is worth noting that violent behaviors are not exclusive to chimps, nor are sexually lubricated exchanges native only to bonobo populations.」
　　[　https://www.britannica.com/explore/savingearth/the-scandalous-social-lives-of-bonobos 2023-05-17, emphasis ours　]　

Modern definitions (that generally disregard history) …excluding politically incorrect concepts and other meanings deemed offensive today; may list only pigeonholed definitions, euphemisms, or meaningless mnemonics)
Chinese: wide; numerous; to spread
Japanese: kanji "dotted cliff" radical
Unihan extended: wide, extensive, broad
EDRDG: dotted cliff radical (no. 53)