Pre-school children who spend time together show one another's personalities, a new research has found. The study shows that environment plays a key role in shaping people's personalities. While genetics still forms the central part of the human psyche（心理），the research finds that personality features are "contagious" （传染的） among our children. "Our finding flies in the face of common assumption that personality can't be changed, " Said Dr. Jennifer Neal, co-author of the study.

The researcher studied the personalities and social networks of two pre-school classes for a full school year. One of the classes was a group of three-year-olds, and the other a group of four-year-olds. Children whose friends were hard-working or outgoing gradually took on these personality features over time. Psychology expert Dr. Emily Dublin said kids are having a far bigger effect on each other than people may realize. 

The new study is not the first to explore the contagious effects of personality features. A 2015 psychology study found that rudeness at work can be contagious as it travels from person to person "like a disease". The study found that seeing a boss being rude to an employee was enough to cause people to be rude to those around them.

The researchers questioned 6, 000 people on the social "climate" in their workplaces, which included offices, hotels and restaurants. They found 75 percent of those who took parts said they had been treated rudely at least once in the past year. And the study also suggests that merely seeing other people suffer rudeness made it more likely that a person would treat their colleagues in the same way. Rudeness could include leaving someone off an invite to a company event, sending unkind emails, finding fault with others or failing to give praise.

Dr. Torkelson believes companies need to be more aware of the harm that rudeness in the workplace can do as it can damage the working environment. She said better training could help to fight against the problem.