Luke 14:7-11 (New International Version)
7 When he noticed how the guests picked the places of honor at the table, he told them this parable: 8 "When someone invites you to a wedding feast, do not take the place of honor, for a person more distinguished than you may have been invited. 9 If so, the host who invited both of you will come and say to you, 'Give this man your seat.' Then, humiliated, you will have to take the least important place. 10 But when you are invited, take the lowest place, so that when your host comes, he will say to you, 'Friend, move up to a better place.' Then you will be honored in the presence of all your fellow guests. 11For everyone who exalts himself will be humbled, and he who humbles himself will be exalted."
Humility as “downward mobility” is clearly seen in Jesus' picture of taking the lowest seat at the table. If a person took a low seat, he might be raised to a higher one, but if he took a high seat to begin with, someone who outranked him might come in and he would then be forced to take a lower seat.
In the first scenario, there was nowhere to go but up, but in the second, no room for gain existed, only shame.