They do not have one collective attitude. Jack believes the beast is real. That's why he puts the pig's head on the sharpened stick; it's a sacrificial offering to the beast. Simon knows for certain that the beast is not a "thing". He sees the dead parachutist that the other boys think is a beast and he has the "conversation" with the Lord of the Flies in which he reveals that he realizes the real entity to be feared on the island is the boys themselves. Piggy seems to know this as well even though he has had no encounters with the dead parachutist or the pig's head. Ralph is uncertain. First he believes the boys are just being typical little kids and hearing things go bump in the night. Then when Sam and Eric see what they believe is the beast, he is far less doubting. At the end, he realizes what Simon knew - that the boys themselves and their inner savagery was what the boys had to fear.