Physical Nature: Easily tired. Low physical endurance. Tense body. Light sleeper. Choosy about foods. May eat only a small range of foods.

Disposition: Mentally active. Shy. Quiet. Introverted. Sensitive to noise. Their attention darts around like a bird. Easily emotionally overwhelmed. Ill at ease in the world. Irritable.

Interested In: Mental activity. Internal stimulation - thoughts. Observing. Small circle of friends. Privacy. Solitude.

Not Interested In: Physical challenges. "Being in the spotlight" (except in their internal fantasizing). Large social gatherings.

In Times of Stress: Needs to go off by her/himself.

Meso Rundown
Physical Body Shape: A solid muscular body with mass centered over the chest (usually broad shoulders).

Physical Nature: Tremendous physical endurance and coordination (the natural athlete). High pain threshold. Sleeps deeply. Eats a lot of "real food."

Disposition: Assertive, active risk taking, physical adventure. Stimulated by danger. Confronts obstacles head on. Courage. Acts decisively. Extroverted.

Interested In: Doing activities. Being outdoors. Being physically active; being physically challenged. "Hard work and hard play" is their motto.

Not Interested In: Keeping still. Being quiet. Finesse and diplomacy.

In Times of Stress: Seeks release in action.

Endo Rundown
Physical Body Shape: A soft, round and cushioned body with mass centered around the belly and hips.

Physical Nature: Sedentary. Loves soft furniture and dislikes exercise. Deep, long sleep. Loves rich, creamy food.

Disposition: Friendly. Easy going. Not easily flustered. Slow, sure, steady and easy pace. Doesn't like to be rushed. Warm. Cheerful.

Interested In: Comfort and friends. Familiar people and familiar surroundings. Food. Social gatherings. Security.

Not Interested In: Taking risks, exercise. A fast paced lifestyle.

In Times of Stress: Turns to friends for support. If friends aren't available, they will turn to food for comfort.

Now what if you're like me and you were not born a meso, but were born an ecto? An ecto is the thin and lanky person. They are the ones who do not have good hand-eye coordination. They are usually introverted and socially awkward. They cannot gain weight, so they usually remain thin until their metabolism slows down around 40; even then some ectos cannot gain weight; they remain the 98 pound weakling all their life. They are picked on at school (so are endos). And by who? Mesos. Ectos will run around the school yard and look "geeky." Meso girls will have ecto or endo boys as friends, but wouldn't think about going out with them on a date. The meso girls want meso boys. The meso boys want meso girls. Actually the ecto and endo boys and girls also want mesos to go out with. Think of all of the fantasizing that teenage boys and girls do when it comes to romance - think of all of the movie stars - they're all mesos! Everybody, when they are young, wants a meso. Mesos have the flash - both in looks and in energy. So no wonder American advertising is so driven toward people being mesos.
Do mesos have any downside to them? Each body type has it's strong points and it's weak points.
Mesos do so well physically that the physical world can occupy all of their attention and time. Mesos aren't usually the people who look into "the whys" so much. Things are going well in the physical world so why question it; just do it. How many men or women who have been philosophers are physically handsome or beautiful? There are some, though you don't usually equate physical good looks with being a person being strongly attracted to philosophy.
Men have a hard enough time getting in touch with their feelings and expressing their feelings. Meso men have a more difficult time in talking about their feelings. "Real men" don't do that. So women, when you're attracted to that gorgeous hunk of a guy know what else may be a part of "the whole package" that comes with the good looks. Again, some mesos can talk about their feelings, but it's usually not a strong point.
Let's talk about anger; everyone has it and some people express it much more than other people. Mesos are the body type that are most prone to expressing anger violently. They have a lot of physical energy, they're not the best at expressing their feelings and they are physically strong. This can lead to quite a temper. The initial yin-yang assessment can help you greatly in understanding more about the possibility of anger. If the initial yin-yang assessment is yin and a person is a meso, it'll give them more yang (beyond the initial yin-yang assessment). If the initial yin-yang assessment is yang and they're a meso - it makes them more prone to violence.

Now tell me what you guys think about this.

If one were to start taking "supplements" that were to drastically improve his body. And change his body type, do you think his personality would change. For instance if a ecto was to change to a meso.

I think that it would looking good and being strong does wonders for the psyche if you ask me.

But would going from big to small meso to ecto, have a similar effect. what do you guys think?

After all, if people's personality traits are pre-determined by their appearance, then all bodybuilders MUST be shallow, thickheaded, vain, stupid, etc, etc...

All the negative stereotypes thrown around about groups of people (bodybuilders included) become real when people start believing in them, and taking them at unquestioned face value.