Information for Gemini twins

We are asking for your help to learn more about the lives and eating habits of young people. You and your family have been part of the Gemini study since you were born. Gemini plans to find out more about how children grow, their eating habits and how they feel about themselves, as they get older.

So far, we have asked your parents lots of questions about your family. Now that you are older, we would like you to tell us about yourself. If you are happy to help, please answer some questions in an online survey and play a short fun online game.

Why have I been asked to take part?

We are asking you to take part because you are a twin and your family have been part of the Gemini study for the past 11-12 years. Twins are special for researchers because they can help us to learn about the influence of nature (genes) and nurture (experience) on health and well-being. We can learn a lot by looking at how similar or different you are to your twin.

Do I have to take part? 

No, it is up to you. Your parents or carers can help you decide. You can also stop at any time. If you decide you don’t want to answer the questions, you and your family can still stay part of the Gemini study.

Why are we doing this study?

You are going through an important transition from childhood to adolescence. You may have just started secondary school.  Every day you are growing and changing, and your hobbies, attitudes and what you eat might also change. Gemini wants to learn more about how young people think and feel during this time.

What will happen if I take part? 

You will need to answer the questions in the online questionnaire (or a paper booklet if you do not have access to the Internet) and play a short fun online game. We encourage all families to complete the questionnaire online: this will save trees and reduce greenhouse gas emissions!

Some questions are about your eating, and what you think about food and your appearance. It shouldn’t take long to answer all the questions, and you can take a break between sections if you like. 

You can access the online questionnaire by clicking 'Take part now’. This will lead to a page where you can access the questionnaire and the game. Once you have read the instructions click 'click here to start the twin questionnaire' and enter the password we sent you in the letter (if you have lost the password contact us). Please enter your Gemini ID, name and date of birth when prompted and agree to the consent form.

Please don't use your browser's navigation buttons (e.g., Back or Refresh) during the study, as this could cause some of your progress to be lost. If you have any technical problems, please try closing your browser and logging in again, or using a different browser. If you need to take a break, or your session is interrupted, you can log in again later by clicking save and return and making a note of the return code. The study website is designed for desktop and laptop computers, or a tablet. However, the online game is not compatible with mobiles and tablets. If you prefer, you can complete hard copies of the questionnaire booklets instead. If you contact us we will send these to you.


When you click on the online game link you will be asked to enter the password again and then to download the software Inquisit.exe: this is perfectly safe and necessary for you to complete the online game. Please enter your Gemini ID when prompted and agree to the consent form before proceeding. You will then be asked for your Gemini ID again, your full name and your date of birth. Please do not do the online game on a mobile phone or tablet.


We have created short instructions videos to help you complete all parts of this data collection. When you click ‘Take Part Now’’ you will see these videos next to the links to the online questionnaires and games.

Rewards for taking part

To thank you for taking part, we will send your family a £10 Love2reward flexecode voucher, which can be used at a wide range of websites (Amazon, iTunes, Lovefilm, etc.).

You will be entered into a prize draw: five families will win a pair of iPad Minis.


The rewards will be awarded once your whole family completes the questionnaires and online games (you, your twin, and your parent).

What might be hard about taking part?

We would like to ask how you feel about food, eating, and your body. This is to understand more about why some children develop healthy eating habits, but others struggle with their feelings about food and their appearance. Don’t worry, there are no right or wrong answers but if you are upset by any questions or feel uncomfortable, you can stop at any time. 

If you decide that you don’t want to take part, that is ok, and you don’t have to say why. If you are worried about anything in the questions, talk to your parents, a teacher or a friend. 

What will happen to all of the information about me?

Everything you tell us will be kept private. Your name will be replaced with a number so no one will know who you are.


We will look at all of the answers from you, and from the other children taking part, and we will write about what we learn. This will help other people understand more about how children’s eating habits develop.

When will I be contacted again?

We would like to send you another letter sometime in the next five years. You do not need to let us know now whether or not you would like to take part again in the future. We will check you are still happy to answer questions the next time we get in touch.

What if something goes wrong?

We will try and help with any questions you have. If you get upset someone will happily talk to you about it. You, or your parents/carers can talk to us by sending an email to

Please click here to download a copy of this information about the study and keep it for future reference. 

Thank you for reading this information

The Gemini Team

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© 2007-present, Gemini Research - Health and Development, all rights reserved. 

Proudly created by Alice Kininmonth

Gemini Research, Department of Behavioural Science and Health, University College London, London, WC1E 7HB | Tel: 020 7679 1263