Psychology of industry is the study of human behaviour which gets influenced by different environmental conditions. Here, psychology of individuals tries to explain the behaviour of an individual and give reasons and so proper treatment if required. So, here, psychological testing plays an important measure to check for the behaviour and so qualified personnel for particular jobs. Psychologists can also advice for environmental conditions of work, like ventilations, hours of work, light, temperature, etc... Also psychological conditions include security of worker, their relation with others, etc...
Psychology of industry also play role in promotions by considers various parameters of an individual that affects his behaviour and so capability.
Industrial Psychology is applied to the workplace as to measure: attitudes of employees and employers, organizational behavior, workplace environment and its effects, and much, much more. It studies such things as personality, cognition, perception, and human development. It looks about the biological side of behavior (which means it really discovers what chemicals aren't at proper levels in a person with a chemical imbalance). So, psychology plays major role in improving human relations and also in solving industrial dispute. Psychology also helps in explaining difference in individuals relating to interests, aptitudes, specialties, intelligence etc. and so in results helps in explaining about a better person personality and requirements that are required in an individual to perform a particular job.
Psychological also helps an individual in dealing with particular conditions or environment while working and so helps in better adjustment and so relief of tension. So, psychology also helps in personal adjustment for prevailing environment.