No, it's different. For instance, gift-giving is a really big deal in Asian cultures. It's not about throwing lots of money around, it's just showing that you're thinking of someone, so gifts can be very small and inexpensive. So gift-giving is certainly a valid love language, just like physical touch, words of affection, etc. Some people just really like to give their loved one small gifts, and some people really like getting them. They can be small clothing items, candies/food, whatever.

Diamonds aren't "small gifts"; they're absurdly expensive ornaments. Their primary purpose is so American women can show off to other women how much money their husbands have. It's a bit like having a really expensive luxury car: it's a signal to others to show you're rich, not a way for someone to show affection to another.

Edit: About Asian cultures, I'll also add, it's just just lovers. Coworkers will frequently get each other small gifts, or gifts for everyone on the team. This is usually small food items, not anything at all expensive. They might do this if they travel somewhere. I had an Asian (i.e., he had just moved from SE Asia for this job) coworker once give everyone on our team some nice variety of tea, for instance.

It's like buying lunch. When your manager does it, you thank him. When your cow-orker does it, you think "what is this guy up to?"

When my manager tried to pay for my lunch, I declined and paid myself (I am from Russia, we had no such tradition at that time). The feelings I had were a mix of: a) is he trying to make me a teacher’s pet? I am not a teacher’s pet; b) is he trying to show that he has some power over me except paying my salary? At lunch break? He has no power over me except paying my salary, I can well afford to buy my own lunch.

An American visiting from other company was completely dumbfounded: Why have you paid yourself?? He is your boss, it’s his responsibility to pay when he invites you to lunch!!

...And I was completely dumbfounded observing his reaction: have Americans no pride?

Why are you suspicious of a coworker buying you lunch?

I sure would be. Why would someone spend that much money on me unless they're a closer relation?

Buying small gifts for coworkers is one thing, but buying lunch is a bit much. I wouldn't spend more than $5 on a gift for a coworker.

Cuz he's making, presumably, the same amount of money I am (or in the same ballpark). So either he got a raise, or he has an agenda...

I have heard that it's good taste for those gifts to be impermanent. Sort of opposite of the diamond.

yes and not actually they are both good for the same reason, IE they don't hold value. This sort of gift is social signalling that you are willing to sacrifice a certain amount of wealth for them. Neither chocolate, flowers or diamonds have good resale value so you are sacrificing for the partners happiness.

Not holding value is a different thing though. The permanent gift creates an obligation to keep it.

>I was always baffled by the idea that some people considered "gifts" to be the most important way to express love.

I'm baffled that you're baffled. Gift-giving is common in every culture, country, and religion in the world.

The function of gift-giving was an early topic of social anthropology, a classic treatment being Mauss' _Essai sur la Don_ [1]. It contains the (to me) stunning Inuit proverb "Gifts make slaves like whips make dogs" - gift-giving binds the recipient to the giver, it leaves them obligated. Which is not the rosy picture we have of it, but worth thinking about in this context (or any other).

1: https://en.wikipedia.org/wiki/The_Gift_(book)