A huge majority of Yemeni men always wear a jambiya. Traditional dress is a striped futa ( loincloth), bare feet or loafers(!) , argyle socks, a raffishly wrapped turban, and a shiny Hong Kong sportcoat over a plaid shirt. Especially for rural Yemenis a Kalashnikov completes stylish dress . Police in the capital try to discourage carrying machine guns in the city without much success,as it is pretty much the equivalent of wearing a tie. The references to masculinity etc have been well established and as jambiyas are worn in front of your belly where an erection would be, it is a moot point.The Yemenis have been described as "backwards, unwashed and primitive" by other Arabs all over the Mideast and even as far as Mauretania who will in the same breath proudly assert " but my ancestors were from very respected families from Yemen". Yemenis were some of the very first Islamic converts and the oldest known mosque is in Yemen.The far southern end of the Arabian Peninsula is considered the original source of all the Semitic peoples which will naturally include Jews as well as all the Islamic Arab tribes.
I was involved in lots of discussion about jambiyas and what they mean to the Yemenis. They are emphatically tribal and status markers and Yemenis will immediately know the origins of a man by his jambiya if other tribal dress variations aren't also visual markers. I saw many Yemenis out grocery shopping who would matter -of-factly hang a bag of raisins from their jambiya hilts to snack on. A small notepad and a pen are also carried often, pushed into the belt behind the hilt. I saw a fellow with a sprig of yellow flowers carried in the same place. Of course the ubiquitous bunch of green qat shoots in plastic bags are also hung from hilts, which are saved for later in the day when most Yemenis gather with their cronies for a qat chewing session.
I don't think I saw a single jambiya, new or old, that had a blade of more than ordinary workmanship.The blades were very uniform, maybe 80% had a single flute and were about evenly divided between solid forgings and the 2 piece welded construction. Northern sibiki/ Wahhabi styles had much finer blades that showed good craftsmanship and considerable ornamentation of chased and engraved designs.
One time I'd seen a man wearing just his scabbard with no jambiya and asked my friends what that was about. Amidst general mirth and cackling I was told he'd been squabbling with a neighbor. The local qadi ( religious scholar/ judge)had confiscated his jambiya and deposited it in the pokey. This was the equivalent of locking up the fellow himself. Because of the very public embarrassment he would do everything possible to quickly resolve the dispute and recover his manhood as it were.
My friends also noted that in spite of how lethal jambiyas look,it is all but taboo to draw your jambiya in anger. Only a hothead or fool would do so as the consequences of tribal feuds ignited from such an act are disastrous in the extreme and can last for generations. It also seemed from the frequent reports of various tribal shootouts that occurred ( over maybe 4 weeks!!)when I was in Sana'a that inflicting fatalities isn't the prime thrust of tribal feuding- it was much more a sort of dangerous and entertaining sport.
The hundreds of jambiyas I saw were fairly uniform in design as far as tribal origins- the styles are very conservative , and for example Sana'a jambiyas are instantly distinguishable from Hadhramaut or Asir. Yemen is a poor country and most jambiyas are of fairly humble quality.That said, whenever possible a Yemeni will own the best jambiya he can afford.
There is a very great distinction of Yemeni and Omani daggers. Both types were traded across the entire Arabian peninsula but in examining old photos we can see that Omani types were favorites of wealthier Saudis and the Yemeni types seem to be more typical of southern Arabian tribes.
Interestingly across the Red Sea in Harar, Ethiopia, there is a large settlement of Yemenis and one sees quite a bit of Yemeni silverwork as well as jambiyas. My Yemeni friends noted that traders often had wives and households in Harar and these ties went back many generations.