Right laydeez, after hobbling up the stairs (lord knows how I'm going to manage when dh goes back to work tomorrow) to find the book I now give you the follow quote from, Wonderweeks:
"Between 49 and 53, you child begins to perceive that her world is changing again. While she is sorting out this new complexity, she will need some extra comfort and support, and this makes her appear fussy and demanding for a while. This fussy period will often last for 4 or 5 weeks, but it can be as short as 3 weeks or as long as 6. If your baby is cranky, watch her closely. There's a good chance she's attempting to master new skills."
Fussy signs:
Cries more often and is more often cranky or fretful
Is cheerful one moment and cries the next
Wants you to keep him busy, or does so more often
Clings to your clothes or wants to be closer to you
Acts unusually sweet
Is mischievous
Throws temper tantrums, or throws them more often
Is jealous
Is more obviously shy with strangers
Wants physical contact to be tighter or closer
Sleeps poorly
Has 'nightmares', or has them more often
Loses appetite
Sometimes just sits there, quietly daydreaming
Sucks his thumb, or does so more often
Reaches for a cuddly toy, or does so more often
Is more babyish (?)
To paraphrase (a lot) Basically up until now the babies have perceived the world in terms of sequences, ie what steps are involved in carrying out each task. This leap will enable them to see things in terms of programmes rather than sequences. Programmes are things that we do regularly, but not necessarily in the same way, the stages are flexible rather than fixed. eg Counting to 10 is a sequence that never changes, things like dusting, laying the table or even going shopping are programmes as they aren't necessarily done the same way every time. Apparently we will see evidence of the leap in their play. They may become interested again in toys they had lost interest in but play with them in a more imaginative or complex way.
Blimey that took a long time to type. Apologies for any typos, I haven't proof read any of it.