Is this a thesis statement? It's supposed to be about the negative effects of ambition. If not how can I make it better?"Having too much ambition can result in taking your self respect and...
Is this a thesis statement?
"Having too much ambition can result in taking your self respect and becoming dishonest and harmful to others."
You have the beginnings of a good thesis statement here. What I think it needs, though, is what we call parallelism. In this particular case, that means that when you have a series in a sentence, you want everything in the series to be in the same form.
For example, look at this sentence:
In my spare time, I like to read, playing the piano, and go to the movies.
This is an awkward sentence because all my verbs are not in the same form. This prevents the sentence from flowing smoothly or having any rhythm. However, I could do this:
In my spare time, I like reading, playing the piano, and going to the movies.
Now all my verbs are in the same form.
In your thesis statement, you have a series of three points you want to make to support your thesis. If we put them in the same form, we might have this:
Having too much ambition can result in losing self-respect, becoming dishonest, and harming others.
You might want to put your points in another verb form, which would be fine, but the idea is to have all of the points in the series in the same form, giving your thesis statement some flow and some rhythm. And, by the way, this is true no matter what kind of sentence you are writing, not just for thesis statements!