According to some management experts, procrastination is like a disease. Once it impacts one person in the office or the study group, it hits everyone in rapid succession. According to Time Management Ninja:
It has been shown time and again that people adapt their habits and behavior to fall in line with others around them. It really doesn’t matter why: whether it is science, social, or just a need to fit in. This can be applied to exercise, health, eating, beliefs, habits, …and yes, productivity.
When speaking of procrastination, Time Management Ninja describes it as "a sickness that can destroy individuals and companies." Putting things off can start in your work life and spread to your personal life. Or, perhaps a friend always chooses to delay projects. Eventually, those habits will spread. Procrastinating one thing can lead to many things—nothing to mess around with!
Others are of the mind that actions are individual, and everyone should take ownership over their own work habits and productivity. Sure, you absorb habits from those close to you, but at the end of the day, you are responsible for your own schoolwork, housework and projects; your friends and coworkers are not.
Calling procrastination "contagious" is just one more excuse on the pile for why you should not start the work in front of you. Procrastination is an individual roadblock, capable of being conquered by you and you alone.