Throughout the story the author keeps repeating the phrase "There must be more money." Both parents have expensive tastes but neither is good at earning money. Here is just one example of how D. H. Lawrence uses the spoken and unspoken words "there must be more money" to create an atmosphere of anxiety.
And so the house came to be haunted by the unspoken phrase: There must be more money! There must be more money! The children could hear it all the time though nobody said it aloud....Behind the shining modern rocking-horse, behind the smart doll's house, a voice would start whispering: "There must be more money! There must be more money!"....And each one saw in the eyes of the other two that they too had heard. "There must be more money! There must be more money!"
When Paul begins winning money and arranges to have it given to his mother without her knowing its true source, the general anxiety only increases. Instead of being satisfied, his mother only wants more and more money. The children pick up her anxiety because children are especially sensitive to their mothers' moods, although they may not be able to comprehend them intellectually or to explain them to one another in so many words. Hester can think of all sorts of ways to spend the new income on luxuries and on things that will improve the family's social status. She buys new furniture and arranges to send Paul to Eton, the most prestigious prep school in England, where he will meet the scions of noble families and then undoubtedly go on to Oxford or Cambridge.
Then something very curious happened. The voices in the house suddenly went mad, like a chorus of frogs on a spring evening. There were certain new furnishings, and Paul had a tutor....There were flowers in the winter, and a blossoming of the luxury Paul's mother had been used to. And yet the voices in the house, behind the sprays of mimosa and almond-blossom, and from under the piles of iridescent cushions, simply trilled and screamed in a sort of ecstasy: "There must be more money! Oh-h-h; there must be more money. Oh, now, now-w! Now-w-w - there must be more money! - more than ever! More than ever!"
This is the principal way in which Lawrence creates an atmosphere of anxiety in the household and within the entire family. The other way is in describing the effect of his mother's greed and the resulting atmosphere of anxiety on Paul. He rides his rocking-horse harder and harder, frightening his sisters and alarming his parents and the servants. This is an effective way of showing Paul's anxiety, because children who are emotionally troubled often display that rocking behavior. It just happens that Paul owns a big rocking-horse; otherwise he might be rocking back and forth on his hands and knees instead. If he were simply rocking on his hands and knees, as many autistic children do, his parents would think there was something seriously the matter with him. But since he has the rocking-horse and has not yet completely outgrown it, his desperate rocking in his effort to force his intuition to provide him the names of winning horses is only regarded as a kind of joyriding, the expenditure of excess youthful energy. In fact, his mother doesn't really care very much about Paul or her other children, as Lawrence makes clear early on.
She had bonny children, yet she felt they had been thrust upon her, and she could not love them. They looked at her coldly, as if they were finding fault with her. And hurriedly she felt she must cover up some fault in herself. Yet what it was that she must cover up she never knew. Nevertheless, when her children were present, she always felt the centre of her heart go hard.
Paul's mother is so preoccupied with spending the riches she is receiving that she pays less attention to her children than ever. This is a phenomenon to be seen in many families where children suffer a sort of benign neglect because both their parents are preoccupied with materialistic concerns. It becomes obvious throughout Lawrence's story that what Paul really wants is not money but his mother's love--and that is something he can never obtain, no matter how hard he rides or how much money he wins. In effect, his mother sells her son for money. And the boy's Uncle Oscar states this moral of the story when he tells her:
"My God, Hester, you're eighty-thousand to the good, and a poor devil of a son to the bad."