In Chapter 4, the littluns are given a fairly lengthy description. This first quote shows how the littluns obeyed and respected Ralph as an adult authority figure:
They obeyed the summons of the conch, partly because Ralph blew it, and he was big enough to be a link with the adult world of authority; and partly because they enjoyed the entertainment of the assemblies. But otherwise they seldom bothered with the biguns and their passionately emotional and corporate life was their own.
They were not very useful with building or hunting. They were often eating, playing, or crying. So, they spent most of the time in their own world. But Ralph and other reasonable boys like Piggy are concerned for their welfare.
In Chapter 5, Ralph calls an assembly to settle the matter on what the "fear" is. Ralph wants them to address the fear for the sake of the littluns and the older boys. When the littluns begin to cry in unity, Maurice makes them laugh to forget their fear:
Maurice saved them. He cried out. “Look at me!” He pretended to fall over. He rubbed his rump and sat on the twister so that he fell in the grass. He downed badly; but Percival and the others noticed and sniffed and laughed. Presently they were all laughing so absurdly that the biguns joined in.
It is mostly Ralph, Piggy, Simon, and Maurice (in this last instance) who show concern for the littluns. Maurice is acting in this spirit of concern for the littluns. In Chapter 6, Ralph and Jack argue over them. Ralph shows concern and Jack could care less:
“Let’s be moving,” said Jack relentlessly, “we’re wasting time.”
“No we’re not. What about the littluns?”
“Sucks to the littluns!”
“Someone’s got to look after them.”
“Nobody has so far.”
“There was no need! Now there is. Piggy’ll look after them.”
In Chapter 7, the boys go to investigate the cliff, leaving Piggy with the littluns. Again, Ralph is the one who shows concern for them and Piggy. Jack dismisses this concern and continues to voice his annoyance and hate for Piggy:
By now, Ralph had no self-consciousness in public thinking but would treat the day’s decisions as though he were playing chess. The only trouble was that he would never be a very good chess player. He thought of the littluns and Piggy. Vividly he imagined Piggy by himself, huddled in a shelter that was silent except for the sounds of nightmare.
The concern for the littluns comes largely from Ralph's leadership and the concern of considerate boys like Piggy and Simon.