Personally I think its not true. Now I have all boys but even then the older 2 are completely different when it comes to PT. My oldest was fully PT in 3 days (day/night, poop trained took about 4 mos b/c he was afirad of that part). My neice has been PT for 18 mos and is STILL in diapers. My middle son is now 3 and while he trained in 3 days, he regressed after a traumatic life event and 6 mos later we are still trying to get him back to being PT.

it all depends on if the child is ready. Ive seen girls who were PT at 18 mos, and girls who were PT at 2 1/2 or 3. Ive seen boys PT at 18 mos and boys who were PT at 2 1/2 or 3.

I feel if a child isnt ready then there is no point in trying to make them train (as with the case of my neice whos been Potty training for over 18 mos now). I think the best thing you can do is introduce it early. my oldest started going pee on the toilet at 19 mos but i didnt call it potty training b/c we just did it to get him used to it before bath time. At 21 mos he peed for the first time. within 2 weeks he was going pee every night before bath and every morning when we woke up but we were NOT potty training, it was just our routine.

can i ask about his diapers.. have u tried another brand? I know some run smaller than others. Target brand in a size 5 seems to be bigger than Luvs size 5, kwim? they also have the bigger kid diapers, not sure what they are called so i gues thats another option if he does out grow diapers. Most kids tend to quit growing at some point though so u dont have to jump diaper sizes so much. My oldest never made it back a 4 (he PT at 2 yrs and 7 or 8 mos). My 3 yr old (just turned 3) has been in size 5s for almost a year (4s fit but he pees so much he needs a 5). Caleb is 13 mos and 3s are still big on him (he grows in length, not weight and in the waist).