Finally getting over that annoying nippy stage, finally starting to really get the whole peeing-outside thing... learning sit and down and come... you were so proud!

"What happened to that sweet, obedience five month old?"  you wonder as your adult-sized dog drags you across the road to meet a total stranger.  

Sorry. Your dog is a teenager, and that means their brain is now goo. 

The amygdala (ah-MIG-da-lah) is the part of your brain responsible for processing emotion and deciding how to behave in a given situation. It is your amygdala which is responsible for that thrill of fear that runs through you when someone taps you on the shoulder unexpectedly, even as you recognize that it's only your spouse returned from their walk. 

Your amygdala screens everything that happens - it gets to make decisions before your consciousness even gets a look at the raw data.

Have you ever slammed on the brakes without knowing why, only to realize that someone was running a red light and would have T-boned your car if you hadn't stopped?

Thank your amygdala. 

It isn't only fear that your amygdala handles, though. All emotion gets processed by the amygdala, and it can send behavior orders to your body without your permission if it thinks there's a good enough reason. When you can't help but laugh, even when you're trying to stop because your laughter is getting embarrassing - you can probably blame your amygdala for that too. 

Thankfully, most of the time, we can control our emotional behavior responses.

As much as you may get the urge to punch someone who is irritating you, or to cry when someone hurts your feelings, often as adults we can inhibit those responses and choose to do something wiser or more dignified. When you are startled by that unexpected tap on the shoulder, you can usually stifle the scream before it happens.

Children can't do that, and neither can puppies. The inhibition neurons in the amygdala aren't fully grown until the entire body is fully mature.

The inhibition neurons are the ones who actually check with the rest of the brain before doing something silly and have the ability to shut down any inappropriate orders the amygdala gave out.

If you've ever started to tap the brakes, only to release them again when you realize that you just saw a shadow, not a child running into the road, that's your inhibition neurons shutting down your amygdala's overreaction.

Imagine an adult arachnophobia sees a plastic spider in a Halloween decoration. Their amygdala goes "AAAARGHHHH spider!!!! Shall we scream and flail and run away???" and the person's wiser parts of the brain analyzes the situation more closely and say, "no! It's just a plastic spider." The adult takes a deep breath and laughs at themselves and walks past the decoration.

A scary experience with a bearded man may get stored in the amygdala and result in that jolt of fear whenever they see a bearded man in the future... despite many more experiences with very nice bearded men. 

The caterpillar brain is metamorphosing into the butterfly of adulthood.

Have you ever cut into a half-developed cocoon? You won't see a half-butterfly, half-caterpillar in there. The caterpillar doesn't slowly grow wings and add legs. 

No, the cocooned caterpillar digests itself and reduces its entire body into a kind of goo. Then that goo reassembles itself as a butterfly.

Really.

The teenage brain does something similar, although not quite so dramatically. First it prunes away a lot of the neurons involved in learning, in order to make room for information super highways. Connections that were made in childhood/puppyhood get strengthened and expanded, while unused connections get snipped away. 

MRIs of human teenagers have found that teenagers actually have LESS brain mass than pre-pubertal children, because the pruning is happening and the new growth isn't completed yet.

It is a time of use it, or lose it. 

The puppy that learned not to jump up on week one will start jumping up, because the amygdala is saying "someone we love is here! I feel SO HAPPY. Shall we go TOTALLY NUTS?" and the pre-frontal cortex just plays The Girl From Ipanema for a while before adding, "...thank you for your patience.  Your call is important to us.  Please stay on the line..." 

...So the dog just explodes with delight and leaps all over the person anyway. 

When the dog sees a black poodle, and remembers that ONE old granny poodle who snapped at them once when they were being obnoxious, the amygdala says, "it's a black poodle! Will it eat us???" and your dog's brain, instead of saying "no, of course not, we've met lots of nice black poodles since then and besides, we were being so rude. Just be nice and we'll be fine",  replies with a blue screen of death.

Enter total inexplicable and irrational terror response. 

Yeah. Pretty much. It's a stage, like the eating-everything stage (which your dog may still be in because some dogs do that throughout their first year) or the "senile and needs to be lifted down the stairs" stage we sometimes get in old age. 

But there are some things you can do. 

Give your teenager lots of time to finish doing their amygdala-mediated emotional behaviors and start using what brains they still have left. Long hours spent relaxing in the park, watching the world go by, can be very beneficial to a teenage dog. Encourage your dog to slow down and sniff the flowers on walks, rather than charging down the road thinking PARK PARK PARK PARK PARK.

Gradual transitions instead of quick ones will give your teenager more time to get in touch with their pre-frontal cortex and actually think instead of just mindlessly reacting. 

You don't have to dump obedience training altogether - in fact, consistency is very important as your dog tests the boundaries of your sanity - but don't be surprised or unhappy if it all falls apart for a while. Your dog really can't help it. Their brain just isn't communicating with itself very well right now, and they are constantly being hijacked by their own amygdala. 

Don't push your teenager too hard, or ask too much.

Your dog's goo-brain is uniquely theirs, and will develop at its own pace based on their breed, genetic makeup, the amount of enrichment they got in early life (studies show rats raised in enriched surroundings matured faster than rats in deprived surroundings), and a zillion other things. There's a lot of research still to be done on dog brain development, for instance the effects of spaying and neutering. 

We know that large breeds mature slower than small breeds. The old Swiss saying for Bernese Mountain dogs is "three year a puppy, three years a good dog, three years an old dog. Anything more is a gift." A chihuahua might be a mature adult by one whereas a Berner may still be a puppy at two and a half. 

But in general, most dogs hit maturity around 18 months of age. Sometimes as late as 24 months or later.

I would expect things to get better by age 2.

Anything more than that is a curse.