The science of toilet training:
What research tells us about timing
© 2007-2010 Gwen Dewar, all rights reserved
When is the best time to begin toilet training? Infancy? 18 months? 24 months? Or even later?
There is surprisingly little research addressing this question. As I note elsewhere,
each age is associated with its own costs and benefits.
But it's fair to make a two general points.
1. The widespread belief that early potty training causes psychological or behavioral problems is not supported by the evidence. As I note below, this idea seems to have arisen because people conflated early training with bad training.
2. Kids who are trained late--i.e., after 32 months--might be at greater risk for developing bladder problems.
For the details, read on.
Part 1: A recent history of toilet training attitudes
Many parents--particularly Western parents--worry that early toilet
training is harmful to children. This idea has been promoted by
pediatricians and child-care professionals. As I will argue below, the
scientific evidence doesn’t back it up. But where did the idea come from
in the first place?
Early potty training got a bad reputation because it was once associated with bad training methods.
the 1920s and 1930s, parents were urged to impose a rigid toilet
training regimen on children before they could walk. Techniques were
coercive, even abusive.
One government manual instructed parents
to enforce “absolute regularity" of bowel movements by inserting a soap
stick in the infant’s rectum at precise times of the day (United States
Department of Labor 1935).
Other prevalent tactics included
scolding and physical punishments for accidents (Hushka 1942; Stendler
1950; Luxem and Christophersen 1994.)
After World War II, the medical establishment began to reject early potty training.
Freudians claimed that early, rigid training caused emotional problems and neuroses later in life.
like Benjamin Spock and T. Berry Brazelton, argued that pushing
children may cause a variety of troubles, including stool withholding,
stool toileting refusal, regression, and
(Leiberman 1972; Brazelton 1962; Brazelton and Sparrow 2004).
development researchers argued that training should not begin until
kids could actively cooperate with the process (Brazelton et al 1999).
Strict timetables for training were abandoned. Instead, parents were
encouraged to let their children’s spontaneous curiosity set the pace.
These changes probably saved many children from harsh training methods.
But reformers seem to have confused methods with timing.
one historical study I’ve read, the author clearly stated that that any
training before 10 months is, by definition, coercive (Hushka 1942).
important point is that “when to train" and “how to train" are
different questions. Bad training methods can cause problems.
But does early timing cause problems? Based on modern studies, the answer appears to be “no."
Part 2: Modern scientific studies
Early training doesn't cause problems
The few scientific studies of
infant toilet training
have reported no negative side effects (Ball 1971; Cederblad 1970;
Smeets et al 1985). These studies focused only on basic skills and did
not track children over the long-term. But the cross-cultural evidence
suggests that long-term toilet training problems are rare (Ainsworth
1967; deVries and deVries 1977).
The evidence for toddler training tells a similar tale. Earlier training is not associated with behavioral problems.
recent American study tracked over 400 children to learn what, if any,
effects timing has on toilet training success (Blum et al 2003).
were enrolled in the study at 17-19 months. Their parents were
interviewed every 2-3 months until they completed daytime potty
training. Researchers compared children who began “intensive"
training—-defined as being asked to use a potty chair or toilet more
than three times a day—-before 27 months with those who began intensive
training after 27 months.
The earlier starters were no more likely
than later starters to experience constipation, stool toileting
refusal, stool withholding, or hiding from parents (Blum et al 2003).
only negative finding was that children trained earlier tended to take
longer to complete training. Kids who starting training between 18-24
months took, on average, 13-14 months. Kids who trained after 27 months
took 10 months or less (Blum et al 2003).
The authors infer from
this result that there is “little benefit" in beginning potty training
between 18 and 27 months (Blum 2003).
However, the study directed
parents to use a gradual, child-oriented approach to potty training. As
a result, the younger participants might have been less prepared for
training, which would have slowed their progress. If parents had been
instructed to actively prepare their children for training, the results
might have differed.
Moreover, the study by Bloom and colleagues
didn’t address training before 18 months. When infant training is the
goal, children may finish within 5-9 months (Smeets et al 1985; Boucke
Other research suggests that later training is associated with problems.
Delayed training might put kids at higher risk for developing bladder problems
A recent case control study interviewed the parents of older kids
(aged 4 – 12) who had been diagnosed with daytime incontinence (Barone
et al 2009). These kids still had trouble suppressing the urge to
urinate. Was there anything in their toilet training history that stood
When the kids were compared with a control group,
researchers found that the incontinent kids were more likely to have
begun toileting training after 32 months.
Previous studies have also reported links between late training and bladder trouble.
Belgian researchers interviewed the parents of kids in grade school and middle school (Bakker et al 2002a, Bakker et al 2002b).
found that school-age kids with bladder problems--like daytime
accidents, bedwetting, and recurrent urinary tract infections--were more
likely to have started toilet training at a later age.
results should be interpreted with caution. The case control study
doesn’t tell us much about causation. And the Belgian study depended on
parents’ recall many years after the fact.
Maybe some toddlers
possess traits that make their parents delay training--and perhaps these
same traits lead to more bladder problems later in life.
too, parents with symptom-free children are more likely to minimize the
effort of toilet training and to forget how early the process began.
But it makes sense that earlier training could reduce the incidence of urinary tract infections.
training helps children learn to completely empty their bladders—-an
ability that reduces the risk of infection (Janson et al 2000; Sillen
and Hanson 2000).
As a result, some researchers recommend that
children with dysfunctional bladders should start training early
(Hellstrom and Sillen 2001).
As for Freud, it’s interesting to
note that Freud never singled out early training as the cause of
personality disorders. He was concerned about any approach to training
that might be regarded as extreme—too early, too late, too strict, too
“libidinous" (Fenichel 1945, p. 305).
In any case, I can find no
scientific studies that link the timing of toilet training with the
later development of emotional disorders. Freud identified certain
personality types that have been confirmed by modern scientific studies.
However, these personality types have NOT been linked to childhood
toilet training experiences (Fisher and Greenberg 1977; Masling 1999).
For more information, be sure to check out my article on
choosing the right potty training age,
as well as these
evidence-based potty training tips.
References: The science of toilet training: What research tells us about timing
Ainsworth N. 1967. Infancy in Uganda. Baltimore: John Hopkins Press.
American Academy of Pediatrics. 2006. Toilet training readiness American Academy of Pediatrics webste. (visited November 24, 2006).
E; Wyndaele JJ. 2000. Changes in the toilet training of children during
the last 60 years: the cause of an increase in lower urinary tract
dysfunction? British journal of Urology, 86(3):248-52.
2002. Research into the influence of potty training on lower urinary
tract dysfunction. Unpublished MD dissertation, Department of urology,
University of Antwerp, Belgium.
Bakker E, van Gool JD, van
Sprundel M, van der Auwera JC, and Wyndaele JJ. 2002b. Results of a
quaestionaire evaluating the effects of different methods of toilet
training on achieving bladder control. British Journal of Urology, 90:
Ball TS. Toilet training an infant Mongoloid at the breast. California mental health digest 9: 80-85.
JG, Jasutkar N, Schneider D. 2009. Later toilet training is associated
with urge incontinence in children. J Pediatr Urol. 5(6):458-61.
NJ, Taubman B, and Nemeth N. 2003. Relationship between age at
initiation of toilet training and duration of training: A prospective
study. Pediatrics, 111: 810-814.
Boucke L. 2003. Infant Potty Basics. Lafayette, CO: White-Boucke Publishing.
Brazelton TB 1962.A child oriented approach to toilet training. Pediatrics, 29: 121-128.
Brazelton TB and Sparrow JD. 2004. Toilet training the Brazelton way. Cambridge, MA: deCapo Press.
TB, Christophersen ER, Frauman AC, Gorski PA, Poole JM, Stadtler AC,
Wright CL. 1999. Instruction, timeliness, and medical influences
affecting toilet training. Pediatrics, 103: 1353-1358.
Pediatric Society. 2000. Toilet learning: Anticipatory guidances with a
child-oriented approach. Paediatrics and Child Heath, 5: 333-5.
M. 1970. A child psychiatric study of Sudanese Arab children. In EJ
Anthrony and C Koupernik (eds), The child in his family. New York:
deVries MW and deVries MR. 1977. Cultural relativity of
toilet training readiness: A perspective from East Africa. Pediatrics,
Fenichel O. 1945. The psychoanalytic theory of neurosis. New York: Norton.
Fisher S and Greenberg RP. 1977. The scientific credibility of Freud’s theories and therapy. New York: Basic Books.
A and Ilg FL. 1943. Infant and child in the culture of today: The
guidance of development in home and nursery school. New York: Harper
Gladh G, Persson D Mattsson S and Lindstrom S. 2000.
Voiding pattern in healthy newborns. Neurourology and urodynamics, 19:
Gorski PA. 1999. Toilet training guidelines: Parents—the role of parents in toilet training. Pediatrics, 103: 362-363.
AL, and Sillen U. 2001. Early potty training advantageous in bladder
dysfunction. Decreases the risk of urinary infection (in Swedish).
Lakartidningen. 98: 3216-9. Ned Tijdschr Geneeskd., 147(1):27-31
BE, Regterschot GJ, Nieuwenhuis EE, Benninga MA, Verwijs W, and
Waelkens JJ. 2003.[Bladder control in 1-4 year old children in the the
Eindhoven and Kempen region (The Netherlands) in 1996 and 1966]
M. 1942. A study of training in voluntary control of urination in a
group of problem children. Psychosomatic Medicine 5: 254-65.
UB, Hanson M, Hanson E, Hellstrom AL, Sillen U. 2000. Voiding pattern
in healthy children 0 to 3 yers old: A longitudinal study. Journal of
Urology 164: 2050-2054.
Largo RH, Molinari L, von Siebenthal K,
and Wolfensberger U. 1996. Does a profound change in toilet-training
affect development of bowel and bladder control? Dev Med Child Neurol.
Lieberman, L. 1972. The changing ideology of
socialization: toilet training, mass media, and society. Int J Contemp
Luxem M and Christophersen E. 1994. Behavioral
toilet training in early childhood: research, practice, and
implications. J Dev Behav Pediatr, 15(5):370-8.
Martin JA, King
DR, Maccoby EE, and Jaklin CN. 1984. Secular trends and individual
differences in toilet-training progress. Journal of Pediatric Psychology
Masling J. 1999. An Evaluation of Empirical Research
Linked to Psychoanalytic Theory. Paper presented on June 11, 1999, at
the Annual Meeting of the Rapaport-Klein Study Group. Accessed online
(November 24, 2006) at
McKeith R. 1973. How children become dry. Child Dev Med., 48/49: 3-32.
O’Connell, D. 2000. As they grow: Your two-year-old. New York: St Martins.
TR, Kolb TM, McAuliffe TL, Simms, MD, Underhill, RL and Lewis M. 2002.
Sequential acquisition of toilet-training skills: A descriptive study of
gender and age differences in normal children. Pediatrics 109: 48-54.
Sears RR, Maccoby EE, and Levin H. 1957. Patterns of childrearing. Evanston, Ill.: Row, Peterson and Company.
U and Hanson E. 2000 Control of voidings means better emptying of the
bladder in children with congenital dilating VUR. British Journal of
Urology, 58: 13.
Smeets PM, Lancioni GE, Ball, TS, and Oliva DS.
1985. Shaping self-initiated toileting in infants. Journal of applied
behavior analysis, 18: 303-308.
Sonna L. 2005. Early-start potty training. New York: McGraw Hill.
Stendler CB. 1950. Sixty years of child training practices: Revolution in the nursery. Pediatrics 36: 122.
Taubman B. 1997. Toilet training and toileting refusal for stool only: A prospective study. Pediatrics, 99: 54-58.
United States Department of labor, Childrens Bureau. 1932. Infant care, publication 8.
CK, Godley ML, Ho, CK, Ransley PG, Duffy PG, Chen CN, Li AK. 1995. Some
new insights into bladder function in infancy. British Journal of
Content of "The Science of toilet training: What research tells us about timing" last updated 4/10