▁ 1 8 , 8 1 8 ▁b ab ies ▁born ▁in ▁the ▁UK ▁in ▁the ▁year ▁ 2 0 0 0 – 2 0 0 1 . ▁ ▁History ▁The ▁M CS ▁is ▁the ▁fourth ▁longitud inal ▁birth ▁coh ort ▁study ▁conducted ▁in ▁the ▁UK . ▁Its ▁aim ▁is ▁to ▁create ▁a ▁multi - pur pose ▁data - set ▁that ▁describes ▁the ▁divers ity ▁of ▁background s ▁into ▁which ▁children ▁are ▁born ▁in ▁the ▁beginning ▁of ▁the ▁ 2 1 st ▁century . ▁The ▁information ▁collected ▁includes ▁topics ▁such ▁as ▁child ▁development , ▁social ▁strat ification ▁and ▁family ▁life ▁in ▁order ▁to ▁identify ▁possible ▁advantages ▁and ▁dis adv antages ▁that ▁the ▁children ▁are ▁facing . ▁ ▁The ▁survey ▁is ▁conducted ▁in ▁different ▁swe eps ▁with ▁the ▁first ▁one ▁concentr ating ▁on ▁the ▁circumstances ▁of ▁the ▁pre gn ancy ▁and ▁birth ▁as ▁well ▁as ▁the ▁first ▁few ▁months ▁of ▁life . ▁This ▁first ▁part ▁of ▁the ▁survey ▁is ▁also ▁important ▁to ▁record ▁the ▁so cio - e conom ic ▁background ▁of ▁the ▁family ▁into ▁which ▁the ▁child ▁is ▁born . ▁The ▁second ▁swe ep ▁took ▁place ▁when ▁the ▁children ▁were ▁about ▁ 3 ▁years ▁of ▁age ▁ ▁and ▁the ▁main ▁focus ▁was ▁on ▁continu ity ▁and ▁change ▁in ▁the ▁family ▁as ▁well ▁as ▁the ▁parent ing ▁environment ▁to ▁extract ▁information ▁about ▁the ▁child ’ s ▁development . ▁In ▁the ▁third ▁swe ep ▁in ▁ 2 0 0 6 , ▁the ▁children ▁were ▁at ▁the ▁age ▁of ▁starting ▁primary ▁school . ▁ ▁The ▁fourth