I believe the answer is: <span>pruning
</span>In psychological term, pruning is the process of eliminating a certain information from our brain in order to be replaced with the information that are deemed more necessary for our everyday use.
In language learning, pruning could happen when after we acquire the knowledge of new language but left them unused.
The answer is "the social-conflict approach".
The social conflict approach is a way to deal with social theory that contends that society is described by different disparities and clashes that reason individuals to act socially, delivering change.
Society, according to the social conflict approach, isn't amicable. It's not steady. Society doesn't create agreeable balance. Truth be told, it's overflowing with imbalance. So this methodology is extremely about investigating imbalances of race, class, sexual orientation, and ethnicity, and the social clashes which result. Basically, these contentions will result in change, changes that will move society.
Condensation if I'm not mistaking.
The missing word in the statement above is: life satisfaction. Most middle-aged adults list life satisfaction as the most important factor in happiness. According to the experiments related to life satisfaction, people become older because they become wiser and more knowledgeable and they begin to see that life would be better. This is based from the psychologists, Yuval Palgi and Doc Shmotkin.