Can any generalisations be made about the psychological reasons for why some people are anorexic whilst others are bulimic?

1. Who becomes anorexic?
While anorexia mostly affects girls and women (85 – 95 percent of anorexics are female), it can also affect boys and men. It was once thought that women of color were shielded from eating disorders by their cultures, which tend to be more accepting of different body sizes. It is not known for sure whether African American, Latina, Asian/Pacific Islander, and American Indian and Alaska Native people develop eating disorders because American culture values thin people. People with different cultural backgrounds may develop eating disorders because it’s hard to adapt to a new culture (a theory called “culture clash”). The stress of trying to live in two different cultures may cause some minorities to develop their eating disorders.

Who becomes bulimic?
Many people think that eating disorders affect only young, upper-class white females. It is true that most bulimics are women (around 85–90 percent). But bulimia affects people from all walks of life, including males, women of color, and even older women. It is not known for sure whether African American, Latina, Asian/Pacific Islander, and American Indian and Alaska Native people develop eating disorders because American culture values thin people. People with different cultural backgrounds may develop eating disorders because it’s hard to adapt to a new culture (a theory called “culture clash”). The stress of trying to live in two different cultures may cause some minorities to develop their eating disorders.

from here

So, it seems, that at least one website simply uses the same description for both while switching bulimia for anorexia. I’ll look around some more. This website has some conclusions as to the difference.

There has been some research on personality differences between anorexics and bulimics, (as measured by the Multidimensional Personality Questionaire). First, both showed lower than average affect (they’re seldom happy or excited) and well-being, as might be expected. They’re both easily subject to stress, also not surprising. Both are low in “social closeness” and high in “alienation”.

But anorexics typically scored much higher in “control” and “emotional/behavior constraint” than bulimics, and anorexics tend to manifest less absorption in sensory experience than bulimics.

In broad generalities, this would suggest that anorexics have a greater ability to resist the urge to eat, and are less likely to enjoy eating.

Trust me that I thought this before I read @thorninmud‘s comment.

Anorexics have control, although they believe they don’t. They feel like they can’t control anything in the world, so the only thing they can control is themselves. They deny themselves food to prove it. They justify it by saying they can’t be too thin. They are striving to look pretty, but the truth is they seek control in a world that had hit them from right and left and left them feeling like they can’t do anything right.

Bulimics, on the other hand, feel like they have huge appetites. They can’t control their appetites. They have no ability to say no. They just feed themselves all kinds of crap. But then, of course, they feel guilty about what they have done, and so they punish themselves and keep themselves from looking fat by purging.

Psychological traits? Well, if you could, I would measure sensuousness and tactility. I suspect that bulimics touch more and are more in the world and appreciate the feel of things from puffy bears on their beds to the taste of food.

Anorexics should be more austere. They should have less stuff around. They won’t like food even if they didn’t want to starve themselves. They won’t get as much pleasure from the taste.

According to this theory, it could be tested in a number of ways. I would look at who goes out dancing more. Who likes sex more. Who hits the restaurants more. Who is involved in relaxed activities more than harsh activities like marathon running. If you counted these things, you would see bulimics should like fun activities more than anorexics.

Go test the theory and see if it describes reality in any useful way.

Anorexia can be about having control all the time over yourself. Bulimia can be about being able to go totally out of control via binging, and then retake that control and undo the damage via purging. Binging can also aid in dissociation, if that’s your thing.

I agree with control and fear/ anxiety issues at the baseline for all emotional conditions.

Why do we do anything from a purely sensual level, because it either tastes good, feels good, makes us happy, and it’s easy to get caught in extremes for some.

Every disorder is just a twist on a normal behavior taken to an extreme in the way the individual copes with their emotional issues.

I could stand to purge today, jk lol

Emotional distress in both cases. I can’t think of any other generalization to include both.