Is laughter contagious? Is it genetically contagious

[Roland Taylor (Network Creator?)]

I was just wondering, because sometimes, when someone hears another person laughing, they begin to laugh without knowing the reason...

I had a friend who would genuinely have a fit for now apparent reason, just because of hearing someone laugh.

I have found that this is not true of everyone, but it's a behaviour that seems almost to run in families. Could it be that laughter is contagious, just as yawning is?

I have heard that yawning is passed on to others because of the human's in-built social etiquette, however there is evidence against this as well?

What do you think, is it contagious, or do we just laugh spontaneously, without reason, because of social etiquette?
Furthermore, does this behaviour run in families?

[StevenBuri]

By the way I want you to find an up to date article by a scientist that isn't considered crazy that says otherwise - or go to your university and as a teacher there who specializes in Biology, and ask them if personality traits are passed down through generations via the parents, and then come back and THEN you can tell me that anything other then GENETIC traits are passed down from the parents to babys. GENETIC traits are traits that are in the dna and control aspects of your life like if you have a hitchhikers thumb, if you have a unibrow, and what color your eyes are. For instance if my mom had blue eyes (which is dominant) she would have the genetic trait Bb (so one of the traits is dominant while another one like say green eyes is recesive) but my dad has green eyes so he would have the genetic trait bb because green is a ressecive trait) then that leaves my 3 brothers to have the traits Bb, Bb, bb, bb which is why my brother and I have hazel (green) eyes whilst my oldest brother and youngest brother have blue eyes. Scientifically proven - fact. And the fact that all you can do is say, ahahahaha look at you little person, we are more then skin and bones (really, didn't know that), its not only genes, gives absolutly zero proof and not even a good argument.
What I have is proven, explained, mapped out, and makes sense - you can't argue with fact, because its fact. That is exactly how my family is, so no matter what you do it makes no difference what you think it is because it has already been proven that genes are the only thing passed down from the parents to the babies. My mom is a tad frantic whilst driving, none of her 'gene' (which it is not a gene at all) got 'passed' down from her to my brothers or I. Genes don't dictate your personality, and the fact that you have no proof and I have the world behind me only proves it. Anyone whos been to school recently has already learned this stuff.

If you really think that you can still win this fight then you need to read the above.

[Roland Taylor (Network Creator?)]

I did all that stuff already... I went through all the alleles etc. I am not just talking about that... Identical twins sometimes are so identical, the die within minutes of one another (not to mention all the other similarities in their lives)

[StevenBuri]

wow dude, they die within minutes of each other... ya think? The were born at the exact same time, are best of buds, have the same genes - although different personalities, and are exposed to the same stuff. Thats like saying that birds that are born on the same day and don't ever get sick or anything sometimes die within minutes of each other, suprise. And even the, "sometimes they die at within minutes of each other" should really be changed to very very rarely. I could probably count the times on 2 hands.

[StevenBuri]

Twins are proof of nothing save proving my point which is that personality is not found in genes and therefore is not passed on from the parents to the babies since twins have the exact same genes and yet different personlaities. (and yes there is the occasional exception that they do have the same personalities).

[booklet]

I don't know little about gene and all that hard stuff about DNA. I just want to make it simple. We laugh because we chose to laugh or not to laugh because we chose not to laugh. Even for no reason.That my opinion.

.........booklet

[Roland Taylor (Network Creator?)]

Simple always wins!

[Roland Taylor (Network Creator?)]

Here's the funniest part, turns out we do pass on behaviour's etc. Through the other chemicals in our body. While it's not fully understood, it is known to happen. Keep laughing for happy children =)