然而另一方面研究也显示,有缺乏对这一理论的证据和其他环境因素也会影响孩子们的认知行为。按Morrow-Tlucak et al,1988 -认知发展也根据不同出生体重等其他因素,孩子的经历,母亲的经历,成长,母亲的教育等等。有时候压力为母乳喂养的母亲她可能需要减少工作时间,可能经历许多心理变化可能不支持母乳喂养的时间较长(尼尔森等人,2005)。
Menkes (2007) suggested that tyrosinemia because of amplified protein intensities in recipe milk may create an expanded occurrence of education inabilities in kids fed with bottle. Rodgers (2008) proposed conceivable intervening components may be contrasts in the middle of bosom and jug drain in osmotic burden or protein and lipid focuses or contrasts in the nourishing circumstance, for example, disease danger and mental impacts. Fergusson et al. (2012) included contrasts in mother/baby communication like a potential go between. It is likewise conceivable (as is recognized by the aforementioned creators) that unrestrained determination toward oneself elements (motherly contrasts or contrasts in the residence setting) might create the detectable contrasts in cognitive improvement.
However on the other hand studies have also revealed that there is lack of evidences for this theory and the other environmental factors also affect the cognitive behaviour of kids. As per Morrow-Tlucak et al, 1988- the cognitive development is also based on various other factors like birth weight, child’s experiences, maternal experiences, upbringing, maternal education etc. It is sometimes stressful for the breast feeding mother as she might need to reduce her working hours and might undergo many psychological changes which might not support them in breast feeding for a longer period (Nelson et al, 2005).