Read Betrayal: Book Three of Allies and Adversaries Page 14

In the many millennia of development of the meta-sentients, much debate was created concerning their ability to experience emotion. Some turned out to be easier than others. Emotions like desire, envy, happiness, satisfaction, even love and hate fit into their programming. But scientists involved in their evolution discovered an eternal arrogance was inherent in their programming. This made two emotions, regret and remorse, impossible to elicit from the meta. The meta believed their actions were perfect; that decisions they made were not subject to debate or questioning. Hence, past actions could never be regretted, and since they believed they never made mistakes, they could not feel regret. Scientists came to believe the first meta to be able to experience those emotions would be the first that would have the potential for true development, the first that might have true sentience.