How did Prince Palamedes recognize Odysseus's trick?

Question

How did Prince Palamedes recognize Odysseus's trick?

Answer 1

Odysseus, who was later called Ulysses by the Romans, was king of Ithaca, a small island on the west coast of Greece. When summoned to join his fellow chieftains in the war against Troy, he could not bear to leave his young wife, Penelope, and their son, Telemachus. He therefore pretended to be insane. To convince everyone of his madness, he plowed the sand along the seashore as though it were a field. But Prince Palamedes, who came for him, recognized this as a trick. To prove it, Palamedes placed little Telemachus in the path of the plow. When Odysseus quickly turned the plow aside to avoid striking his son, all saw that his madness was a pretense. So Odysseus fitted 12 ships and went to Troy.  

Answer 2

How did he recognize it?  Odysseus has a well-known reputation for being tricky and deceitful, and so Palamedes was willing to bet that Odysseus was up to his old tricks in this situation.  If Palamedes ended up being wrong and Telemachus were to have been killed, he would not have to worry about repercussions because that would mean Odysseus was really crazy.  It was a no risk situation for Palamedes.

Answer 3

From Wikipedia: When Helen was abducted by Paris of Troy, Menelaus called upon the other suitors to honour their oaths and help him to retrieve her, thus forging the Trojan War. Odysseus tried to avoid it by feigning lunacy, as an oracle had prophesied a long-delayed return home for him if he went. He hooked a donkey and an ox to his plough (as they have different stride lengths, hindering the efficiency of the plough) and sowing his fields with salt. Palamedes, at the behest of Menelaus' brother Agamemnon, sought to disprove Odysseus' madness, and placed Telemachus, Odysseus's infant son, in front of the plough. Odysseus veered the plough away from his son, thus destroying his ruse. Odysseus held a grudge against Palamedes during the war for dragging him away from his home.