Your hair holds more than you think. Tiny amounts of hair can help researchers understand how our bodies respond to stress—particularly by measuring cortisol, a hormone linked with stress that becomes embedded in hair strands. Unlike one-off stress measures, hair analysis lets us build a picture of longer-term stress levels across the UK population.
We’re inviting Understanding Society participants to contribute a small hair sample from each member of their household. It’s entirely your choice whether to take part, but every sample makes a valuable difference. By taking part, you help us ensure people of all ages, backgrounds and regions are fairly represented—giving us a clearer understanding of the nation’s wellbeing.
If you choose to take part, we’ll send you a simple collection kit containing clear step-by-step instructions and everything needed to collect and send back the sample safely.
We’d like you to collect a small sample of hair, from the back of the head, just below the crown. The sample needs to be about 1cm in diameter – roughly the width of a pencil.
Yes, you can. Just make sure that you allow the hair sample to dry for a few minutes before packing it.
Yes it is! Hair type doesn’t affect our ability to measure cortisol.
No, we need the sample to be taken from the back of the head, just below the crown of the head. If you’re not sure about collecting the sample by yourself, please ask a friend or family member to help you.
Yes, you can provide a few smaller snips—as long as they are taken from the same spot and level on the head.
Yes, you can. Asking your hairdresser, or a friend or family member, to help you can make the sample collection a lot easier. Just show the instructions to them so they can correctly collect the sample for you.
Because the newest hair—closest to the scalp—best reflects recent cortisol levels. The hair closest to the scalp is the newest and reflects recent hormone levels better than the ends of hair.
We will analyse the hair to check the sample quality. This is so we can test whether hair samples collected by participants can be used to analyse cortisol effectively.
After the sample has been analysed, it will be destroyed.
Please do not collect a hair sample if:
No. We will analyse samples to check the quality of the information we can get from the hair, rather than providing individual results.
The hair collection kit includes a small pair of scissors. These have a rounded tip to the blade, but please be careful when using them. There are no other risks in taking part.
Taking part is completely voluntary. If some members of your household want to take part and others don’t, that’s also fine. We value every sample we do receive, and there is no pressure to provide one if you’d prefer not to.
Yes. Personal identifying information, like names or addresses, are not attached to the hair sample. Each sample is given an anonymous code as soon as we receive it. We will keep all information about you safe and secure. The results of the study will never include any names or addresses. The information collected is used for research purposes only and will be dealt with according to the principles of the Data Protection Act and the General Data Protection Regulation (GDPR).
Once we have finished the study the anonymised data are made available from the UK Data Service, other secure data repositories or by the study team, to trusted researchers. All research reports are written in a way that no-one can work out that you took part in the study.
You can find the Privacy Notice for this project here.
Yes—you can withdraw at any point without giving a reason. We can remove any personal data not yet archived, though we’re unable to retract information already accessed securely by approved researchers.
Researchers at the Institute for Social and Economic Research (ISER) at the University of Essex are running the study. If you return a hair sample we will send it to the Dresden LABservice, Germany for analysis. More information about the Dresden LABservice can be found on their website: https://dresden-labservice.com/.
Yes. Before any research like this can be done it is looked at carefully by an Ethics Committee. In this case, the study has been approved by the University of Essex Ethics Sub-Committee 1, reference: ETH2526-0465.
If you have any concerns about any aspect of the study, or if you have a complaint, in the first instance please contact our Participant Communications Team on Freephone 0800 252 853 or by email contact@understanding.ac.uk. They will pass the information onto the principal investigator of the project, Professor Michaela Benzeval.
If are still concerned, or if you think your complaint has not been addressed to your satisfaction, or you feel that you cannot approach the principal investigator, please contact the departmental Director of Research in the department responsible for this project, Professor Paul Clarke, pclarke@essex.ac.uk.
If you are still not satisfied, please contact the University of Essex REO Research Integrity Manager (reo-integrity@essex.ac.uk).
If you have any questions or comments for us, please contact the Participant Communications Team by emailing contact@understandingsociety.ac.uk or by calling Freephone 0800 252 853.