Curiosity killed the cat.

A parcel arrived from Amazon the other day, not for me.  It was still in the same position a day later.  There was, I was told, no reason to open it because the contents were the books that had been ordered.

I can't do that.  I can't leave a parcel or letter unopened.  I was self appointed postwoman for our department at work just in case there was something important (or, let's be honest, just interesting) lurking the bundle which could otherwise be left for hours.  I can't let a telephone ring, even if I'm on the point leaving the house.  I must find out what it is.  This curiosity of mine has been useful too - it worked well in IT because I couldn't rest until I had found the root of a problem.  I see or hear something and wonder, "Why is that?".

According to psychologists, curiosity is defined as a need, thirst or desire for knowledge.  A cat wants to know what made that sound or caused that movement but humans can be curious about things that may not even exist (and many will make a decision on little or no evidence - also known as jumping to a conclusion).  These show two different types of curiosity behaviour - one is exploratory and the other could be called thinking.  There's another division between broad and deep curiosity. Some people want to know about all sorts of different things while others to know as much as they can find about a single topic and will keep on delving more and more deeply.

If something odd happens, or a difference shows up, some people will notice and accept it as just that, others won't notice at all, but the curious will want to know why.  I've seen curiosity described as being on the border between order and chaos, so you could think of it as an attempt to maintain a sense of order, to explain away the potential chaos.

Roget's Thesaurus says that the absence of curiosity is boredom.  I don't think I'll ever be bored.

P.S. no. 1
1885, Sir Francis Galton wrote a paper called “The Measurement of Fidget.” [Another good detour to explore here: he was the cousin of Charles Darwin and an early fingerprint specialist]. He noted that in an audience, people will fidget about once a minute.  The ones who are interested in the subject will fidget less often than those who are bored, and they will get their fidgeting over quickly. 

P.S. no. 2
Curiosity killed the cat
Information made him fat.
That was the rhyme I was told as a child, I suspect to keep me out of mischief.  Since looking up one or two things for this post, I've learnt another ending: "satisfaction brought him back" which I much prefer.

P.S. no. 3
I've read that curiosity is a predictor of happiness.  I don't know whether that's true or scientifically investigated, but I'm happy to hear it. :)