Why increase positions when profitable, and not when losing?

Answer: I thought about this question all night. If you average down twice after a loss, if the averaging down fails, you will lose three times the capital. If it succeeds, you might have just made a profit but will need to exit, because that's human nature: willing to accept risk and hold positions when losing, but when profitable, we dislike risk and are reluctant to hold positions, preferring to take early profits. However, when increasing positions while profitable, if it fails, you only lose once when losing, but when making money, you can earn three times. Which one do you think is more cost-effective?