Research Wonder: Expression of Gratitude and Survey Quality

What's a Research Wonder?  Read this to find out...

Neuroscientists have demonstrated that if you ask yourself, "What am I grateful for?", it will raise dopamine and serotonin in the brain, both of which help boost your mood when you feel down.  You don't even have to find something that you are grateful for - just simply searching for something has the same effect.

I WONDER...

If a simple expression of gratitude is given during a survey, how might that gratitude impact the other answers in the survey?

AND I WONDER...

Can asking a respondent to express gratitude while reading a survey invitation boost their likelihood to respond to the survey?

AND I ALSO WONDER...

How much do inadvertent gratitude expressions or thoughts during survey responses influence the responses themselves?  Do we need to take care in where we ask questions that may lead to thoughts of gratitude, so that we do not bias the following questions?