"we conclude that feather pecking in chickens and schizophrenia in humans have numerous common features"

# The light response in chickens divergently selected for feather pecking behavior reveals mechanistic insights towards psychiatric disorders

Background: Feather pecking is a serious behavioral disorder in chickens that has a considerable impact on animal welfare and poses an economic burden for poultry farming. To study the underlying genetics of feather pecking animals were divergently selected for feather pecking over 15 generations based on estimated breeding values for the behavior.

Methods and results: By characterizing the transcriptomes of whole brains isolated from high and low feather pecking chickens in response to light stimulation we discovered a putative dysregulation of micro RNA processing caused by a lack of Dicer1. This results in a prominent downregulation of the GABRB2 gene and other GABA receptor transcripts, which might cause a constant high level of excitation in the brains of high feather pecking chickens. Moreover, our results point towards an increase in immune system-related transcripts that may be caused by higher interferon concentrations due to Dicer1 downregulation.

Conclusion: Based on our results, we conclude that feather pecking in chickens and schizophrenia in humans have numerous common features. For instance, a Dicer1 dependent disruption of miRNA biogenesis and the lack of GABRB2 expression have been linked to schizophrenia pathogenesis. Furthermore, disturbed circadian rhythms and dysregulation of genes involved in the immune system are common features of both conditions.


…Do animals suffer from mental illness?

I mean, it’s very common for dogs to exhibit separation anxiety from their humans, and we all know cats are a little bit nuts, so I don’t see why not.

Interesting that we would have some commonalities with chickens. I wonder which scientist was like, “chickens + feather pecking = schizophrenia.”

But I digress.

I think it’s wild that animals also have “mental illness”— if we can call it that.

The truth is, animals are a lot more complex than we give them credit for.

And we are, after all, animals ourselves.


At first glance I thought this might be satirical. Certainly one thing we share with feather pecking hens is high levels of anxiety.

On a more sociological note it’s quite revealing that for the authors, feather pecking should, not unlike sz, find its ultimate cause not in high levels of anxiety, often associated with bad living conditions, but in their genes. I’m not questioning the role genes play in both these conditions, only the allegedly self-evident nature of the logical primacy of genes over environment when framing causality.

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I would think so. There is no reason why their brains can’t have a chemical imbalance, or be wired the wrong way, or they have nerve problems, etc…

Yep, when I leave for work as soon as I say “bye” my dog knows that means I am leaving and he starts barking like crazy, then when I get home he comes to greet me and is all happy.

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@Headspark Your dog might be bipolar then.


I don’t know, when everyone is home he completely fine. I think it’s just separation anxiety. He gets upset when I leave and gets happy when I come home, otherwise he is fine the rest of the time.

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Very true.

…As a side note:

Do you remember Koko the gorilla?

Researchers taught her how to sign and she could communicate back to them.

Now they’ve got “talking” dogs:

…I think this is a super-interesting area of study that could shed some light on the “animal condition.”

Perhaps we can gain a little insight on how our furry friends are feeling.

Just thought it was cool :sweat_smile: :upside_down_face:.


Of course, you can always ask for a second opinion. I’d need to interview the dog to gauge its true mental state.


Yeah, I heard bout Koko a long time ago, very cool!

I haven’t heard about that, but very interesting!

Yeah, I think we have more in common with other animals than is commonly thought.

It is! :sunglasses:

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I thought whatever dumb cluck shows up he’s the head of the pack

slowly plucks a fell bird, removing all trace of feathers. Presenting his new creation to the world, he lifts it high in the air

Behold! A man!


My cat does. She spent three years living in a child’s bedroom before being rehomed to me because the other cats in the home terrorized her. She had bald spots from pulling out her hair when she bathed. She’s still quirky, but she’s got a proper coat again. It’s been almost four years and she is still unwinding from that trauma so far as we can tell.


Poor thing :broken_heart:.

Trauma is very real for just about all species, and can manifest in many ways, like how your cat was losing her hair, or even aggressive or territorial behaviors.

So, so happy you guys were able to give her a nice home :slightly_smiling_face: :+1:.