Twins

[Shakira]

Since I've been on this forum I have noticed that there is a significant amount of twins who are MDers. I'm a twin too and I am a MDer. I also believe my relationship with my twin sister is a major part of why I daydream in the first place. I do not have a good relationship with my twin and very rarely communicate with her directly. She is not an MDer but our younger brother is. She is also the only person I've attempted to open up to about my daydreaming(huge fail btw). Are any of you twins on here? What is your relationship like with your twin? And is she /he a MDer?

[Philip Dorrell]

It would be nice to get a precise handle on "significant".

Firstly, it seems reasonable to assume that there is no particular selection effect - that twins are not particularly more likely to join an internet forum than anyone else (unless the forum is actually twin-related).

A caveat to the above is that twin birth rates are different in different countries, and probably the membership of this forum is not evenly selected from the total world population. However, in US and UK, which account for most native English speakers, about 3.3% of people are twins. (Also, we could use the highest twin rate in any country as an upper bound for the probability of being twins, and a significance result based on that would still be valid.)

It then boils down to simple arithmetic, and a bit of statistics theory:

• How many people are there on this forum? = N
• How many people on this forum are twins? = n
• Calculate n/N.
• Is the answer significantly different from 0.033? (If we get to this point, the required calculation is described at http://www.real-statistics.com/binomial-and-related-distributions/h....)

Going to the Members page, it tells me that N=4570. So the null hypothesis estimate for n is 150. In other words we have to find that there are significantly more than 150 twins on this forum before we can get excited about it (subject to the caveat that if we do a systematic survey, probably not all 4570 signed-up members will respond to it).

[Cemre]

I have a twin sister and she knows my situations. ABD, being the great sister she is, she helps me daydream by acting like one of my characters! Our parents don't know but we sometimes ''play'' for hours. She doesn't have MDD but she still helps mr. And she says that she likes playing with me. I don't know if she really feels like that though.

[Cemre]

Sorry there is a mistake on my comment. ABD is and it's because of my phone. Sorry :(