There are a lot of joke comments here which is a real shame because this is an actual issue that causes actual behavioral problems in not just cats but domestic animals in general. :/
-Timidness, flinching from touch
-Food insecurity (cat snarls / growls / attacks anyone trying to get near their food bowl)
-Hyper aggression, seemingly unprovoked attacking of hands / arms / feet / ankles / etc.
-(This is a really common big one in males:) Urination outside the box / deliberate marking behavior
Some cats will also develop neurotic behaviors like obsessive self-grooming, but these are less common and vary from animal to animal whereas the above are pretty observable in lots of cases.
If you have a cat struggling with destructive anxiety symptoms like these I would highly recommend A) talking to a vet about getting in contact with a behaviorist and B) try and observe your cat to see what triggers the worst of the behaviors. Does the animal respond poorly to having people stood over it? Does it get better or worse at certain times of day, and if so what goes on inside & outside at those times? Do certain smells, sounds, etc. garner a reaction? Do certain types of play make things better or worse? Is your house set up in such a way that your cat frequently finds itself sandwiched into corners with people or other pets between it and the nearest way out? (Hallways with closed doors, U-shaped kitchen cupboard/counter layouts, etc.)
At the risk of sounding like a shill there's a show you can watch online dealing with "problem" cats called My Cat From Hell that originated on I think Animal Planet, and the host is actually really damn good at his job. Absolutely still seek advice from a vet or animal behaviorist, but a couple episodes might give you a better idea of what to look for.
We had a cat that was depressed for most of her life. She used to live almost all her life under a bed, coming out only to shit, pee and eat. She was afraid of everything that made any little noise.
One time some workers had to work on my building and this really messed her up. She would pee everywhere, she wouldn’t eat anymore and stuff. The vet gave us a medicine that calmed her and eventually she cured her depression altogether. She became the sweetest animal this world had ever seen, she never meowed when somebody took her in her arms, she purred when she felt there was someone of use in the next 2 feet of her, she was a fat, soft, cuddly angel.
We had to put her down when she was getting too sick for her age. She went from fat ball of fur to “you can feel her spine if you pet her” level of thinness, she didn’t take a shit for days. My mom said that she didn’t suffer and after she died they found she was full of shit and blood and would have suffered a lot soon.
My cat runs away from the litter box with a forlorn cry whenever she drops a whoppurr.
I feel like I should read "Everybody Poops" to her.
If your cat is screaming “low self confidence” or any other phrase, you should take it to a vet.
I did have a very timid cat who'd been found on the streets.
He'd spook very easily at loud noises, or even sometimes his toys being tossed his way.
He liked having me around to protect him when he explored a new environment.
He loved me, he liked my housemate, and he tolerated our other housemate and his dog (...Well, it took a lot of work to get him used to the dog, but he got there in the end) but was terrified of strangers. He'd freak out whenever there was someone at the door. At one point my housemate's sister moved in and tried to befriend him by feeding him every night - it would've worked eventually, but he was still wary of her when she moved back home a couple of weeks later.
He hated being separated from me - he'd follow me around the house, and even cry at the bathroom door when I had to use the toilet. (I tried letting him in, but then he'd cry at the bathroom door because he didn't like being trapped.)
He'd often refuse to eat unless I cut up his food for him and fork-fed or hand-fed him each bite. I should note that this might have been entirely because of his stomach problems, as he unfortunately turned out to have had the disease FIP in his guts the whole time I had him.
He also spent a lot of time under my bed, where he felt nice and safe. Towards the end of his life, as he got sicker, the poor little bub was spending ever-increasing amounts of time under there.
Don’t have a cat but I found through personal experience that
OP you have to keep in consideration that cats are both predators and prey.
That is where they get their amazing reaction time from.
Naturally that also gives them a skittish side.
The all clear sign for a cat is looking at it then slowly blinking and looking away.
This shows the cat that you are aware of its presence but don't consider it a threat.
One of my cats is extremely clingy to the point that I can pet her and cuddle her for literal hours, then if I leave the room for 5 minutes and come back, she starts mewing (its more of a squeak, tbh) and demanding more attention. She runs from anyone who doesn't live in the house (sometimes even then), hides when I play guitar, and waits until the ends of songs to run into the room to demand attention,and if you walk towards her, she flees (as though she expects to be kicked out of the way, though we've never done anything of the sort). I think her previous owners abused/neglected her and she still carries the fear and lack of confidence 3 years later (and she seems to recognize that I'll actually pay attention to her and love her and can't waste a second of it). She hates being picked up, is terrified of boxes, stays in the basement until late at night or really early in the morning, and will instantly retreat to the basement if she is upstairs and you walk towards her. She also doesn't seem to feel satisfied with just laying in your lap most of the time, nor when she's being pet with anything less than the maximum number of hands available. It has to be 100% undivided attention or she will yell, throw herself at whatever you're holding, or give up and leave (takes awhile though), and it's rare that it ever takes less than 30 straight minutes of this (usually closer to an hour or two) before she'll decide she's satisfied and walk away on her own.
The other one, however, I've had since a very young kitten, and he is cuddly and low key clingy (he'll follow me around the house and gets mad if I'm behind a closed door), but he's also a cocky, narcissistic little shit who isn't afraid to let you know when it is or isn't a good time to pet him and/or snuggle. Oh, and he's also pretty convinced he can beat me up (there's no empirical evidence to support this).
Doesn’t want to interact with you when you’re around but immediately looks for you when you’re gone.
I found my cat on the street and was unable to locate its owner. Probably a good thing, since it seems like he came from an abusive household.
Some of the things he used to do:
* often walk around with the tail down, and in a slow, cautious way, acting very skittish if any noise happened
* if you were in tight quarters with him, he would bolt out of there
* if you petted him for more than 10s, he would bite and scratch. It was probably the only way to get out of being "cuddle raped" - I think his previous house had undisciplined small kids, because:
* he is very fearful of hearing kids voices on TV, and ran away hiding when we had someone over with a baby, refusing to come out even for food
* has nightmares where he wakes up hissing or running in fear
I am happy to say that this is all reversible. He is currently sleeping in my lap, after a lengthy petting and purring session, which I never thought was possible 3 years ago. He walks proudly, tail high, and is very playful. He still is terrified of kids and has nightmares sometimes, but, overall, he is now a happy, confident cat.
Oh man, I'm not sure where to find it, but Jackson Galaxy (the weird cat behaviourist guy) has some great segments on cats with low confidence.
Basically, most of the time when a cat has low confidence, it's usually because it doesn't feel secure in its ownership of its home. So giving them more things and places to help them reclaim ownership - scratch posts, cat towers, elevated walkways can help with that.
As for mannerisms that indicate low confidence, it really depends on the cat! It can manifest itself as outright aggression (biting, scratching, hissing) or skittishness, but one of the big ones is litterbox avoidance.
Tucking its paws and sinking its head while in catloaf.
My cats just think I’m a bigger cat. I hide from them and jump out to scare them. I kick their toys around. I tease and play with them way too much. But they all just want to lay on me and purr. Best feeling in the world