More Awesome Than You!

I've read somewhere that 5 seashells on souvenir shelf actually make bladder decay faster, and all member of the family carry its effect everywhere they go. My question is, do other boosts (skill, friendship, romance) act the same way as seashell? If a Sim has 5 far east dolls on souvenir shelf at home lot, will he and his family get the boost when they're skilling at community lot as well?

Yes, all vacation collections affect members of the owning family, anywhere, and no-one else.

Excellent! I was just coming to ask the very same question myself.

I haven't tried arranging souvenirs yet, but 5 seashells make bladder decay faster? Why would I want that? Is it permanent?

Yes.

Unless you have some sort of odd pants-wetting fetish, or have a special sim in mind, you don't.

Until the collection is dismantled, I believe.

Are these bonuses stackable?  With themselves or with other bonuses?

I'd imagine they are with other bonuses, but I'm not sure about additional collections of the same type.

Also, I know that viewing the voodoo doll collection causes a Sim to go crazy (i.e. chased by bees), but does it have a permanent effect like the others?

I think so Denimjo, I think that is what Pescado uses for Sim-Rohina ;)

No, Uglybutt doesn't have a collection of that, and I think the voodoo doll collection only affects sims that view it, but I haven't obviously collected that many voodoo dolls in one house. :P Uglybutt being chased by bees comes from the Ugly Butt Controller.

So, is there a accurate list of  effects somewhere? Snooty Sims claims 5 seashells make bladder decay slower, but they usually seem to get their info from the Prima Guide and the BBS. http://www.snootysims.com/infoindex.php?id=collectables

The Seashell Collection is Bladder Decay -> 700 for Adults and Elders. The Prima Guide's information is lies and propaganda created to encourage you to make your sims piss thmselves to satisfy the EAxis pee fetish.
The Asian Collection is +200 IQ for Adults/Elders, stacks with all other +IQs.
The Voodoo Doll collection gets you chased by BEES anytime you look at it.
The Mountain and Island collections improve Friendly and Romantic Social yields, but the effect is not apparently perceptible.

No IQ boost to younger sims at all?

Nope. I think it may be intended more as a remedial learning benefit, rather than something to accelerate the already insane learn bonii available for sims you breed. Of course, the result is that it's about as useful as tits on a bull at this stage in the game. And Death to all Nesses.

I put up multiple shelves with 5 of the same shell souvenirs to see if the decay would be accumulative.  It does seem that the bladder decay has increased with each shelf of 5 shell I add.  I am wondering if it is just my imagination or does adding multiple shelves increase the effect?

I have not accumulated enough of the other souvenirs yet in order to test them in the same fashion.

Imagination. A collection either exists or it does not. Multiple copies only serve as redundancy in case one is eaten by a fire or something. If the Seashell collection stacked, Brynne would explode due to being unable to pee faster than her bladder would fill.

Thanks for the clarification on that.  I honestly couldn't tell for sure if it was decaying faster or not.

Someone at EA saw Demolition Man may too many times.

I have yet to even figure out where the souvenir shelf is in the buy catalog.  ???

It's categorized under Surfaces-Shelves, along with OFB display shelves.