Changing toilet training trends

Toilet training is happening later than it used to, particularly in higher-income contexts. In the UK, children were toilet trained, on average, by 28 months in the 1950s [1], but by the 2000s, this had risen to nearly 37 months [2]. In contrast, in many parts of the world, children still toilet train earlier—for example, at 22 months in Türkiye [3] and 24 months in Jordan [4]. 

While there is no universal agreement on the "right" time to toilet train [5], research shows that most children are developmentally ready by 18–30 months [6]. Experts also agree that this biological readiness has remained stable over time [2, 7-9]. Toilet training by 30 months aligns with most children’s developmental abilities and is linked to benefits like greater independence, self-regulation, and confidence, especially when approached in a supportive and responsive way [5, 6].  

In many communities, particularly in traditional or lower- and middle-income contexts where nappy/diaper use might be limited, some children even begin toilet training from birth through a practice referred to by some as elimination communication. This involves caregivers closely observing their baby’s cues and natural rhythms to help them go to the toilet outside of a diaper. By gently holding the baby in a secure, supported squatting position at appropriate times, caregivers can respond to and nurture the baby’s emerging body awareness. Research suggests this approach strengthens the caregiver-child bond and supports emotional development [10]. 

Taken together, children's biological readiness has likely remained the same over time; in the past, children in higher-income contexts were toilet trained earlier [1, 8], and many children in other parts of the world still train at a younger age today [2-4, 11-13], with some becoming continent as early as 9-12 months [14]. This suggests that toilet training delays are not due to biological changes but rather to shifts in social, cultural, and environmental factors, as well as responsible adults’ capability, opportunity, and motivation to support the process. 

Why does this matter? 
Delayed toilet training can have real impacts: 

• Health risks – Prolonged diaper use can increase the risk of urinary tract infections and affect children’s mental health and well-being [15, 16] 
• Psychosocial and developmental impacts – Prolonged diaper use may make it harder for children to recognize their body’s signals [17] and impact the natural connection between parent and child [10]. This could lead to more frequent unexplained crying, increased stress in the parent-child relationship, and emotional difficulties [10, 18-20]. 
• School challenges – Teachers report disruptions in classrooms due to children not being toilet trained [21, 22] 
• Financial strain – Responsible adults spend more money on diapers for longer 
• Environmental impacts – More disposable diaper waste contributes to plastic pollution and intensifies environmental sustainability challenges [23-25]. 

What does this mean? 
Scientific research and expert consensus indicate that there is no single "right" time for toilet training. However, evidence suggests that delaying it beyond 30 months comes with certain risks, while starting earlier—even from birth—can be done safely with many health, wellbeing and environmental benefits for all involved. 

What is causing the delay? 
If children’s biological readiness for toilet training has not changed, what is driving this shift? A range of individual, social and material factors likely play a role, but we don’t fully understand why toilet training is happening later in some places and not others. 

That is where the Big Toilet Project comes in! 
The Big Toilet Project is the first global study to understand how and when children are toilet trained worldwide. We’re exploring what works best for families to find solutions that benefit everyone. 

By learning from parents’ and responsible adults’ lived experiences across different contexts, we aim to help everyone navigate toilet training with confidence. 

But we really cannot do this without you. If this topic impacts you and you have thoughts to share, we would love to hear from you. Join our study to share your experiences and help make toilet training gentler for families and the environment! 


Find out more: 
[1] Brazelton, T.B., A child-oriented approach to toilet training. Pediatrics, 1962. 29(1): p. 121-128. 
[2] Blum, N.J., B. Taubman, and N. Nemeth, Why is toilet training occurring at older ages? A study of factors associated with later training. The journal of pediatrics, 2004. 145(1): p. 107-111. 
[3] Tarhan, H., et al., Toilet training age and influencing factors: a multicenter study. The Turkish journal of pediatrics, 2015. 57(2): p. 172-176. 
[4] Albaramki, J.H., M.A. Allawama, and A.-M.F. Yousef, Toilet training and influencing factors that affect initiation and duration of training: A cross sectional study. Iranian Journal of Pediatrics, 2017. 27(3). 
[5] de Carvalho Mrad, F.C., et al., Toilet training methods in children with normal neuropsychomotor development: A systematic review. Journal of Pediatric Urology, 2021. 17(5): p. 635-643. 
[6]. ERIC. Potty training: how to start & best age to potty train. 2023  [cited 2024 30 September]; Available from: https://eric.org.uk/potty-training/. 
[7]. Blum, N.J., B. Taubman, and N. Nemeth, Relationship between age at initiation of toilet training and duration of training: a prospective study. Pediatrics, 2003. 111(4): p. 810-814. 
[8]. Bakker, E. and J.-J. Wyndaele, Changes in the toilet training of children during the last 60 years: the cause of an increase in lower urinary tract dysfunction? BJU international, 2000. 86(3): p. 248-252. 
[9] Schum, T.R., et al., Factors associated with toilet training in the 1990s. Ambulatory Pediatrics, 2001. 1(2): p. 79-86. 
[10] Thorpe, M., The Psychological Advantages of Enhanced Sensitive Attunement Through Nappy-Free Elimination Communication. Ata: Journal of Psychotherapy Aotearoa New Zealand, 2014. 18(2): p. 127-139. 
[11] Choby, B.A. and S. George, Toilet training. American Family Physician, 2008. 78(9): p. 1059-1064. 
[12] Hooman, N., et al., Toilet training in Iranian children: a cross-sectional study. Iranian journal of pediatrics, 2013. 23(2): p. 154. 
[13] Duong, T.H., et al., Urinary bladder control during the first 3 years of life in healthy children in Vietnam–A comparison study with Swedish children. Journal of pediatric urology, 2013. 9(6): p. 700-706. 
[14] Duong, T.H., U.-B. Jansson, and A.-L. Hellström, Vietnamese mothers' experiences with potty training procedure for children from birth to 2 years of age. Journal of pediatric urology, 2013. 9(6): p. 808-814. 
[15] Li, X., et al., Delayed in toilet training association with pediatric lower urinary tract dysfunction: a systematic review and meta-analysis. Journal of Pediatric Urology, 2020. 16(3): p. 352. e1-352. e8. 
[16] Kostekci, Y.E., et al., Evaluation of the effects of the toilet training process on the children's quality of life. Pediatrics International, 2023. 65(1): p. e15508. 
[17] ERIC. Why are children potty training later?  [cited 2025 21/02/25]; Available from: https://eric.org.uk/why-are-children-potty-training-later/. 
[18] Jordan, G.J., et al., Elimination communication contributes to a reduction in unexplained infant crying. Medical hypotheses, 2020. 142: p. 109811. 
[19] Taubman, B. and M. Buzby, Overflow encopresis and stool toileting refusal during toilet training: A prospective study on the effect of therapeutic efficacy. The Journal of pediatrics, 1997. 131(5): p. 768-771. 
[20] Luxem, M. and E. Christophersen, Behavioral toilet training in early childhood: research, practice, and implications. Journal of Developmental & Behavioral Pediatrics, 1994. 15(5): p. 370-378. 
[21] Kindred². School Readiness Survey. 2024  [cited 2024 30 September]; Available from: https://kindredsquared.org.uk/wp-content/uploads/2024/02/Kindred-Squared-School-Readiness-Report-February-2024.pdf. 
[22] van Nunen, K., et al., Parents’ views on toilet training (TT) A quantitative study to identify the beliefs and attitudes of parents concerning TT. Journal of Child Health Care, 2015. 19(2): p. 265-274. 
[23] White, H.L., et al., Open defaecation by proxy: Tackling the increase of disposable diapers in waste piles in informal settlements. International Journal of Hygiene and Environmental Health, 2023. 250: p. 114171. 
[24] Notten, P., A. Gower, and Y. Lewis, Single-use nappies and their alternatives. Recommendations From From Life Cycle Assessments. United Nations Environ. Program, 2021: p. 1-45. 
[25] DEFRA, Life Cycle Assessment of Disposable and Reusable Nappies in the UK 2023 — EV0493, F.a.R.A. Defra - Department for Environment, Editor. 2023, Defra - Department for Environment, Food and Rural Affairs: London.