He could be, but 14 mos is a little early to tell. It could just be that he's going through a phase of separation anxiety. For your sake, I hope that's all it is. Two of my three kids are "spirited". The oldest is 9. I started noticing that she seemed very intense, very willful, very EVERYTHING at about 15-18 months of age. I didn't know any different because she was my oldest, but by the time she was three, I knew I had my work cut out for me. She continues to be quite challenging and has only gotten more strong willed, defiant, and persistent every year. My middle child is a dream (thank goodness) because my 2 yr is the most intense of them all. At least now I have some experience with this, and I know what to do and not to do this time around!
If it does seem like he's going to be spirited, I highly recommend the book Raising Your Spirited Child by Mary Sheedy Kurcinka. This book was such a revelation to me. It helped me understand why my daughter is the way she is. I only wish I'd discovered it a lot sooner than I did. The thing we have struggled with the most is disciplining her. Spirited kids want to be in control all the time, and respond very poorly to authoritative directives, yelling, scolding etc...I was raised in a very authoritative household, as was my husband, so our instinct is to say something like "Go upstairs, put your pajamas on and brush your teeth". Sounds pretty simple, right? But things are never simple with spirited kids. They want to be in control, so if we want things to be peaceful, we have to say "Would you rather have your reading time first, or put your jammies on and brush your teeth first?" When we give her a choice, she's more apt to cooperate. We try to give her choices whenever it's possible and realistic. Some things are negotiable, others are not. You have to lay the ground rules down early for the non-negotiable things, then try to choose your battles on other things. Spirited toddlers need a lot of warning before a transition, and they need to know what to expect. I know my 2 yr old is spirited so I'm always trying to give him a lot of warning before we do anything. I'll say "after we eat, we're going to get dressed". Then, I remind him again when I'm wiping his hands, "now we're going to get dressed". I try not to let him see if I'm stressed because that really affects him. If he can tell I'm getting frustrated with my daughter, he'll actually come up and hit me. He behaves best when everyone is calm and using quiet voices. Yelling never works with spirited kids. It fuels their fire and they just yell back. I try to keep my tone very calm almost monotonous. When my 2 yr old is in the middle of a fit, I will pick him up and whisper very softly in his ear. It calms him down so fast because he wants to hear what I'm saying. I just tell him "it's ok, I know you're angry, I know you want ___ right now, I understand." Then I try to redirect him or get his attention on something else. Anyway, I've written a novel but this is what has helped me, and works for me. Best wishes!