An interesting dive on what hygral fatigue is and the supporting evidence as well as the evidence against it.
Sarah Ingle video
Afobe Atoyebi video
Science-y hair blog article
Sura Kamil blog article
Secondary Ion Mass Spectrometric investigation of penetration of coconut oil and mineral oils into human hair fibers: Relevance to hair damage” Published in Journal of Cosmetic Science , 2001 , Volume 52 , Issue 3 , pp. 169–184
Lee Y, Kim YD, Hyun HJ, Pi LQ, Jin X, Lee WS. Hair shaft damage from heat and drying time of hair dryer. Ann Dermatol. 2011 Nov;23(4):455-62. doi: 10.5021/ad.2011.23.4.455. Epub 2011 Nov 3. PMID: 22148012; PMCID: PMC3229938.
Stam PB, Kratz RF, White HJ. The Swelling of Human Hair in Water and Water Vapor. Textile Research Journal. 1952;22(7):448-465. doi:10.1177/004051755202200702
(Couldn't find a free link to this one)
Gamez-Garcia, M. The cracking of human hair cuticles by cyclical thermal stresses. 1998 May. Journal of the Society of Cosmetic Chemists 49(3):141-153
Yang FC, Zhang Y, Rheinstädter MC. The structure of people's hair. PeerJ. 2014 Oct 14;2:e619. doi: 10.7717/peerj.619. PMID: 25332846; PMCID: PMC4201279.
Franbourg A, Hallegot P, Baltenneck F, Toutain C, Leroy F. Current research on ethnic hair. J Am Acad Dermatol. 2003 Jun;48(6 Suppl):S115-9. doi: 10.1067/mjd.2003.277. PMID: 12789163.
Forgot to add that welshiecurlgirl's instagram post is here.
Had to edit because postimage was very low res if you have the free plan so had to upload to imgur, still looking for alternatives to imgur.