I need a word for someone who thinks that they won't become successful or will fail?
a person who surrenders easily or is subject to defeatism.
defeatism: the attitude, policy, or conduct of a person who admits, expects, or no longer resists defeat, as because of a conviction that further struggle or effort is futile; pessimistic resignation.
- a person who habitually sees or anticipates the worst or is disposed to be gloomy.
Not confident; hesitant - Oxford Dictionaries
An unconfident person will attempt a task but not in a confident manner, fearing that they will trip up in some way.
a person who says something will not work or is not possible : a person who denies, refuses, or opposes something: - Merriam-Webster
that would mean they are actually a pessimist, but it is actually a roundabout way of saying it. I'm not a pessimist, just an enthusiastic naysayer! or He naysayed his own prospects.
A person who predicts Disaster: - Oxford Dictionaries
You could also try: Doomsayers in the political party think we'll loose the war, but there are no rules against "doom-saying" something much more local, like your own prospects.
The pessimist on the lifeguard competition team was a real doomsayer, he couldn't be quiet about how his team was too slow when dragging the backboard out of the water just before the final round!
Depending on the context, you can use loser as someone who has already lost before starting.
A person who loses; one who fails to win or thrive. wiktionary
If you want be less familiar, you can use pessimistic or negative.
From wiktionary :
Marked by pessimism and little hopefulness; expecting the worst.
Pertaining to the worst-case scenario.
And from same source :
- Not tending to see the bright side of things.
You may also consider fatalist, though I like some of the other answers better.
From the beginning of the linked article (added emphasis):
Fatalism generally refers to any of the following ideas:
- The view that we are powerless to do anything other than what we actually do. Included in this is that man has no power to influence the future, or indeed, his own actions. This belief is very similar to predeterminism.
- An attitude of resignation in the face of some future event or events which are thought to be inevitable. Friedrich Nietzsche named this idea with "Turkish fatalism" in his book The Wanderer and His Shadow.
- That actions are free, but nevertheless work toward an inevitable end. This belief is very similar to compatibilist predestination.
- That acceptance is appropriate, rather than resistance against inevitability. This belief is very similar to defeatism.