The mass psychology of humanity forces us to act in similar patterns this has been noted throughout history (dating back to the Romans). 

Also, there is a psychology behind it too.

Bigger drop at end of year.Great Recession was the same...tech crash too.I'm on my phone so can't pull up the charts, but it's the natural psychology behind the market.After this stimulus passes,  likely a jump will happen and you'll feel you missed the bottom.

I am currently working as a case manager in Los Angeles for the developmentally disabled population and planning to return to school for a Master's in counseling psychology and license (somewhere 1-2 years from today).

He knew about business, legal issues, tax issues, marketing, sales, promotion, networking, and most importantly he knew about people (psychology).The first thing he did was tell me that I have two ears and one mouth, and I should listen more than I talk.Second thing he did was have me read "How to Win Friends and Influence People" by Dale Carnegie.Then he taught me how to set appointments was home sellers, go out to their home, and write up a letter of intent to purchase or lease.He said to me, "your job is to bring me potential home sellers will consider a creative offer."

Goes to show the psychology that if you make someone an offer, it forces them to consider it!   

This next part is going to sound left field but what about the psychology behind it being free.  

A lot of times in fear our first psychological response is to fight, in this case the enemy is their tenant.

In my MBA course, my favorite class was psychology of investing.

It was the psychology or emotions that fed the Strike fever as people were swept up in the sentiment rather than looking at it realistically.