Which of the following statement about the passage is NOT true?

1) 

Social communication of elderly grandmothers who spend times babysitting their grandchildren increase.

2) 

In a mutual relationship between grandmothers and grandchildren both sides take advantages.

3) 

Those grandmothers who have high social interaction may suffer from some mental problems like depression.

4) 

Grandmothers who spend more than a day weekly for taking care of their grandchildren may get some mental diseases.