In rejecting the offer of Chryses, Agamemnon ignores the norms of exchange behavior made concrete by the expression of the common opinion of everyone else in favor of what pleases his own heart's desire (literally, 'to Agamemnon, to his heart'). David Elmer (2013, p. 42-46) has shown that the verb 'to please' that is used here, handanein, is "an essential component of the Iliad's decision-making vocabulary" (p. 44), in which it functions as "a way of signaling divergence from an otherwise cohesive collective will (p. 42)." He also argues that an authoritarian, individualistic preference overriding the collective will is not normative behavior in Homeric society, but its opposite. The norm in decision-making in the Iliad is for the collective will to be decisive (Elmer 2013, Chapter 1). Furthermore, Agamemnon's divergent response represents a failure to perceive the interwoven social and sacral consequences of his act. Agamemnon himself is not only the titular leader of the whole expedition to Troy on his brother's behalf, manifested in his possession of the epithet anax andrōn 'lord of men' (an expression that is used of him 49 of the 54 times it occurs in the Homeric and Hesiodic poems), but he is also the wielder of the sacrificial knife (Hitch 2009, Chapter 4), to which we can compare the role of Chryses as the old man who prays/curses and who bears wreaths on a golden skēptron 'staff/sceptre' (1.14-15): we have discussed above the overt sacred/social aspects of the system of exchange: see the comments on Iliad 1.13-15.
Reference:
Hitch, Sarah. 2009. King of Sacrifice: Ritual and Royal Authority in the Iliad. Washington, available online at http://chs.harvard.edu/CHS/article/display/6167