"weak mentality" is correct and usable in written English.
You can use it to refer to someone who lacks strength of mind, or cannot cope well with emotional or psychological distress. For example, "His weak mentality made it difficult for him to cope with the difficulties of his job."
Tamura also discussed dominant problematic mentalities.
We should have them too.'"In a commentary published in Strategic Review, an English-language policy journal based in Indonesia, Mr Widjajanto says the armed forces have suffered for decades from a "weak state" mentality that makes it impossible to push through more initiatives to create a modern fighting force.
A marginalizing "sticks and stones" understanding of what "counts" as "real" pain is evident not only in the statements of many professors, but in the large number of comments that quickly followed the Times piece, where readers categorized trigger warnings as "coddling" a "weak" "victim-mentality".
Rousseau, Kant, and Schopenhauer all declared that women possess characters and mentalities too weak to produce genius.
The old cold warriors thought they could improve the national character by invading Iraq -- in that way banishing post-Vietnam ambivalence about using force and toughening up what they saw as the Clintonesque 60's mentality -- a weak, pinprick-bombing, if-it-feels-good-do-it attitude.
But the problem with a war on drugs, and an ensuing war on gangs, is the weaker side adopts a siege mentality, closing itself off from the outside world.
The wide-ranging reforms to Britain's benefits system have been beset by "weak management, poor governance" and a "fortress mentality" that has so far wasted £34 million of taxpayers' money, the Government's own auditors conclude today.
The government's own auditors have concluded that Duncan Smith's flagship reform is an IT Horlicks – not their exact words, you understand, though they did chuck in "weak management", "poor governance" and a "fortress mentality".
Rather than build connections with those who struggled alongside her, Wanda severed relationships and willed herself not to be "weak-minded" like her parents: "if my mentality were different, then most definitely I would just be stuck like them".
