In Michael Cook's play Jacob's Wake, it is Wayne who is seemingly the most successful of the lot. His Aunt Mary has taught him the importance of being educated. He has finished college and is the only one of Winston and Rosie's children to have a comfortable life: even to the point that he sends money home to his parents.
At first glance, Wayne seems to be decent enough. His father and brother torment him mercilessly. His behavior borders on child-like in Mary's company—the aunt who almost raised him. But we find that he can also be whiney. He resents his brother Alonzo, but awards him and his friends government contracts. In truth, Wayne is an unethical man...a crooked politician.
Mary has a great deal of influence on Wayne. She has been hoping that her father (Skipper) will die soon.
MARY looks up. An expression of near hatred crossing her face.
Why don't you just die and leave us alone.
Mary's attitude cannot help but to have rubbed off on Wayne. It is Wayne that brings home the paperwork to have Skipper committed to an asylum (the "Mental"), and convinced his brother Alonzo to forge their father's signature to make it happen.
When he tells Mary, stage direction notes:
Hope flares up in her.
...Will it take long?
I think we can get him off your hands within the week.
Wayne...I knew you wouldn't let me down...Oh, I'm so excited! I should be sorry—or ashamed—but all I can feel is relief.
Based on the almost unnatural relationship between the two, we can infer that Wayne takes these steps for Mary's sake. Alonzo says as much:
Aunt Mary's been at ye, hasn't she? She's behind this.
Look. We're all worried about mother. How much more of this can she take.
The hell ye are...
Alonzo has his worries about what Wayne plans. And he knows his brother enough to see through his empty excuses that it's for the benefit of anyone other than himself.
Wayne may want Skipper gone also because Skipper is not taken in by Wayne's position or success. Some money must be coming in or the family is able to live rent-free for Skipper must own the house. (Alonzo also notes that Skipper has gold hidden somewhere.) Skipper accuses them:
Living off me. Grandchildren...Not one o' ye a man...Ye've got no God. And ye've got no guts. Ye're nothin', the lot of ye.
Wayne tries to convince the others that Skipper is losing it: that he doesn't know Wayne, or any of them. Alonzo disagrees:
He knows, brother. He knows too well.
When Winston discovers what Wayne has been up to, he is furious. He tries to shoot his son with his gun. Wayne makes excuses that it is for Skipper's "own good." Skipper leaving will make things better for everyone: he'll be taken care of and receive good medical care. He insists that Skipper will live longer, too. He looks to Alonzo to support him, but Alonzo wants nothing to do with what has been primarily Wayne's plan.
Mary's wish to see her father out of the house. He will no longer defy her; she won't need to be indebted to him for his charity; and, she wants her "share" of Skipper's estate. All of these things have deeply influenced Wayne to engage in such a plot. After all, he comes home sometimes once a year, or not at all. Skipper is no inconvenience to him. In recognizing Wayne's motivation, we not only see how weak and flawed Wayne's character is, but we learn through him just how hateful and ungrateful a child Mary truly is.
Wayne is eager to have Skipper, his father, put into a "Mental" in order to reduce the burden of caring for him but also to gain control of Skipper's possessions. Each of Skipper's sons has secret guilt from past or present and none behave with love or responsibility.