Matthew writes that their mother, Salome, made the request, but Mark records that James and John did the asking. There are perhaps three ways we can look at this:

First, Salome may have been trying to ensure her sons received the recognition or position she thought they deserved, perhaps selfishly overlooking the others. James and John were certainly of age to speak for themselves. Why did their mother have to do it? It is something to weigh in terms of their thunderous zeal. Were they at this point hiding behind Mom?

Second, they selfishly sought the position for themselves without regard for the other disciples. Intent on securing their place beside Christ, they were arrogantly playing "climb the ladder" over the backs of their fellows. This could account for both Jesus' reply concerning their being willing to suffer as He did and the other disciples' displeased reactions.

Third, and more plausible, they were truly zealously dedicated to serving Christ, and they were willing to do whatever it took. Speaking of James, he appears to have been a man who was ready and willing to undertake whatever task was called for, as evidenced by his martyrdom. It also seems that he did not mind taking a back seat, perhaps to his younger brother John. Herbert Lockyer, in All the Apostles of the Bible, describes James as one who was "resolute, vigorous, active and forceful, while John was contemplative, intuitive and reflective." James and John do not appear to have been selfish, but men of action ready to meet a challenge. Perhaps we could compare them to athletes who have the mindset that they should be the one batting in the bottom of the ninth down by a run with a man on base, two outs, and two strikes—ready for the challenge!