July 9, 2018-Misreporting studies’ conclusions is a favourite tactic of those opposed to Joint Custody

Some researchers misrepresent the significance of their "data". Prof Nielsen discusses six such studies; here is an excerpt re one Australian study:

In an Australian study commissioned by the government, toddlers (ages 2-3) had worse outcomes in JPC on two of the six measures of well-being (McIntosh et al., 2011). Because this one study has so often been misrepresented in the media and in academic circles (Nielsen, 2014b; Warshak, 2014), it merits more careful attention than the other 59 studies.

The 19 JPC toddlers scored lower on a 3 question test of "persistence at tasks" and lower on 3 questions asking how often they tried to get their mother's attention and how often they looked at her. Neither of these two measures had any established validity or reliability, in contrast to the instruments used to measure children's outcomes in the other 59 studies.

Nevertheless, on the basis of these two invalid measures, these researchers concluded that JPC toddlers were less securely attached to their mothers and less persistent at tasks than SPC toddlers. The 22 JPC toddlers also scored more poorly than 191 SPC toddlers on a validated "problem behavior" scale (refusing to eat, clinging to the mother when she tried to leave, hitting the mother).

Again, these researchers interpreted this finding as a negative outcome of JPC.

In fact, however, JPC toddlers' scores were well within the normal range and were not significantly different from the scores of 50% of the toddlers with married and with separated parents in the general population. On the other four validated measures of well-being, JPC and SPC children were not significantly different.

Linda Nielsen (2018): Joint versus sole physical custody: Outcomes for children independent of family income or parental conflict, Journal of Child Custody, DOI: 10.1080/15379418.2017.1422414, at pp. 10 - 11.