Deciding To Hold Back Your Child [POLL]

My wife and I have a tough decision to make about my 5 year old son. He's finishing up his Kindergarten year, and we are torn about whether or not to hold him back. When we enrolled him in Kindergarten this year, he was borderline for the age cutoff date. He really could have gone either way. We decided to send him.

While he's had a great year, we are going back and forth about holding him back. While 1st grade is a big jump, we are more concerned about how his young age will affect him in middle school and high school...and even college to some extent.

I can't really think of too many drawbacks to holding him back a year in Kindergarten. If I am wrong...he'll thrive. If I am right...I'll be giving him the best chance at success. If I send him to first grade next year...and I am wrong...it might set him up for unnecessary struggles throughout his academic career.

I'm curious to hear from parents who thought about doing this with their kids. Did you do it or not? How did it work out for your kids? Any regrets?