Miss Strangeworth sees the town as her town. Her grandfather built the first house on Pleasant Street, as she proudly tells tourists, and this gives her a sense of proprietorship over those who live in the town. As such, Adela feels entitled to wear the mantle of local moral guardian, which involves doing all she can to root out the least sign of what she regards as immorality.

That's why she writes poison pen letters to various people in the town. Although the letters are thoroughly nasty and detestable, Miss Strangeworth genuinely thinks it's necessary for her to write them in order to maintain a high moral climate in town. The irony here is inescapable; Miss Strangeworth engages in immoral actions for the good of morality.

This bizarre and delusional attitude ultimately stems from what we saw earlier: Miss Strangeworth's proprietorial attitude to the town and its inhabitants. So long as the old lady genuinely thinks that this is her town and that she therefore has the right to act as the guardian of its moral climate, then she will continue to write such horrible letters.

Even when Adela gets a taste of her own medicine, she shows no regret for her actions. Instead, she cries silently for the wickedness of the world. In other words, she's not wicked; other people are. In her own mind, at least, she's still the paragon of virtue.

It might seem like a facetious answer to say that Miss Strangeworth writes letters to others because there would be little point in writing them to herself. However, the story shows that Miss Strangeworth focuses on the flaws of others partly because she lacks the gift of introspection. She regards herself, her house, her roses, and everything she owns as the height of perfection. Mistakes are only made by other people. Even when buying her groceries from Mr. Lewis at the beginning of the story, she reproaches him for failing to remind her to purchase some tea, rather than assuming, as most people would, that it is her own responsibility to remember what groceries she needs. Throughout the story, she sees everyone's flaws except her own.

This minor incident at the beginning of the story demonstrates another characteristic of Miss Strangeworth's which leads her to write the letters. She enjoys power, control, manipulation, and the sense that she is sitting in judgment over lesser mortals. She has not forgotten to buy tea from Mr. Lewis; she merely wants to train him to follow her whims. Jackson says that Miss Strangeworth "sometimes found herself thinking that the town belonged to her." She has a strongly territorial attitude, constantly emphasizing the contributions her family have made to the town, and is resentful that others are insufficiently impressed by her importance. Writing her poison pen letters is a way of exercising power over those around her without engaging in open conflict.

Miss Strangeworth writes poison pen letters to others because she has not developed healthy strategies to help her deal with her anger and aggression. She represses her feelings in order to keep up the appearance of sweetness and goodness that is so important to her ego and self-perception.

But as Freud wrote, what is repressed always comes back in other forms. Miss Strangeworth's aggressive feelings towards her neighbors come out in the form of her destructive, spiteful letters, meant to wound and cause pain. She writes what she cannot allow herself to say, or even fully acknowledge to herself, outside of the letters.

The letters show projection, a psychological defense mechanism in which people assign feelings and desires they find unacceptable onto others. Miss Strangeworth can't accept that the "evil" she finds "unchecked in the world" resides in her. She projects her feelings of self-loathing and her secret wishes onto others. It is most likely she who feels people are laughing at her or who wants to steal the petty cash from the grocer's register. But because her ego is fragile and because she works extremely hard to keep up the illusion that she is pure and superior to her neighbors, she can't accept these ideas might be her own and so accuses others of them.

At seventy-one, Miss Strangeworth has a host of unresolved psychological problems and repressions and might benefit from a good therapist to help her sort them out.

In Shirley Jackson's short story "The Possibility of Evil," Miss Strangeworth is an elderly lady of the town who feels a moral obligation to warn other people of the potential evils that may befall them in life. She writes anonymous letters to people in order to "open their eyes" to "possible evil lurking nearby." The paragraph of the story that explains her motive for writing the letters also says that Miss Strangeworth "never concerned herself with facts" in the letters since she felt it was important to raise people's level of suspicion. We are told that Miss Strangeworth's opinion on the matter is that "as long as evil existed unchecked in the world, it was Miss Strangeworth's duty to keep her town alert to it."

Some of the "evils" that she has forced people to consider are of the more mundane sort, such as adultery and the birth of a child with retardation. Other imagined evils are more elaborate, such as the idea that someone's nephew might bribe a surgeon to fatally botch that person's upcoming surgery in order for the nephew to maybe receive his inheritance sooner. She has been ruining people's relationships and sense of security for an entire year with this letter-writing hobby. Unfortunately for Miss Strangeworth, the vigilance that she has been trying to teach to her neighbors is ultimately turned against her. When one letter recipient discovers that she is the author of the rude letters that have been received all over town, Miss Strangeworth's beloved rose garden is vengefully destroyed.

Miss Strangeworth has developed some very distorted thinking and an unhealthy proprietary interest in a place "she had never spent more than a day outside." She believes that "there wouldn't have been a town here at all if it hadn't been for my grandfather and the lumber mill."

Because her entire life of seventy-one years has been spent in the same place, her range of experience is quite narrow. She is a reactionary who believes that the values she has embraced all her life must continue, and her letter-writing campaign is a pathological exercise in attempting to force her beliefs on others. The rigidity of her habits is demonstrated when she goes to Mr. Lewis's grocery and chides him for "forgetting that I always buy my tea on Tuesday." She is so self-absorbed that she doesn't stop to consider that Mr. Lewis has responsibilities beyond catering to her rituals—or that others have the right to live their lives as they see fit.

The hateful letters that Miss Strangeworth writes are an outward manifestation of her self-righteousness. It cannot be reasonably said that her letters are meant as constructive criticism. Instead, they are deliberately hurtful and do not recommend any corrective action. Because Miss Strangeworth's life is empty, it allows her plenty of time to observe and sit in judgment of others.

Why does Miss Strangeworth secretly warn people of the possibility of evil in "The Possibility of Evil"?

Miss Strangeworth has been writing her anonymous poison-pen letters for about one year and is getting a lot of enjoyment out of her new hobby. It would seem that she does not understand her true motives for writing these letters or how much anxiety and discord she is causing in her little community. She tells herself that it is her civic duty because she is the oldest surviving member of the town's founding family. This seems like a rationalization. This sweet little old lady has a strong desire to be important. 

Yes, we all crave attention. We want to be important, immortal. We want to do things that will make people exclaim, “Isn’t he wonderful?”

The urge to be outstanding is a fundamental necessity in our lives. All of us, at all times, crave attention. Self-consciousness, even reclusiveness, springs from the desire to be important.   
--Lajos Egri 

Etiam sapientibus cupido gloriae novissima exuitur.
“The thirst for fame is the last thing of all to be laid aside by wise men.”
--Tacitus 

I now perceive an immense omission in my psychology: the deepest principle of human nature is the craving to be appreciated.
--William James 

To be a human being means to possess a feeling of inferiority, which constantly presses towards its own conquest....The greater the feeling of inferiority that has been experienced, the more powerful is the urge for conquest and the more violent the emotional agitation.
--Alfred Adler

It can also be seen from the letters and the people to whom they are addressed that Miss Strangeworth is filled with envy and jealousy. She is an old maid who has never been loved and never had her dream of being a mother fulfilled. She is really a pitiful case, in spite of the fact that she is a busybody and a troublemaker. She has written several letters to Helen Crane hinting that the six-month-old daughter who is the light of her life may be mentally retarded. On the day of the story she is writing a similar letter to Don Crane, Helen's husband. Why pick on these people? Because they are in love and are thrilled to have a new baby. Her letters will spoil things for them. They will be afraid to make love and conceive another child. They will feel less pleased with the baby they already have. And there is probably not a thing wrong with their baby--only a "possibility."

Miss Strangeworth has caused serious problems for Linda Stewart and Dave Harris, a couple of teenagers who are in love and probably intend to get married some day. Why pick on these kids? They love each other and are happy together. Miss Strangeworth has never experienced these things. She has written to Linda's parents suggesting the possibility that the two kids have gone beyond the usual teenage necking and that Linda might get pregnant. 

Some people will try to spoil things for others out of envy and jealousy. It is not to hard to recognize such people by little things they say and little questions they ask. If you feel worse after having talked to them, it is a good sign that you should stay away from them. Oddly enough, the children seem to sense that Miss Strangeworth is not the nice little old lady she appears to be.

Most of the children stood back respectfully as Miss Strangeworth passed, silenced briefly in her presence, and some of the older children greeted her; saying soberly, "Hello, Miss Strangeworth."

In every one of the cases recorded in the story it can be seen that Miss Strangeworth is unconsciously attempting to create discord between others who have relationships she lacks. Eris, the Goddess of Discord, is said to have caused the Trojan War because she was, understandably. not invited to a banquet held for all the other divinities. The ancient Greeks, who derived their gods and goddesses from human characteristics, must have recognized that creating discord was a significant human trait and that it was motivated by bitterness at feeling left out.

What is the purpose of the letters that Miss Strangeworth sends in "The Possibility of Evil"?

It would appear that Miss Strangeworth does not understand her own motive or motives for writing her anonymous letters. She rationalizes that it is her civic duty to keep the citizens of her town alerted to the possibilities of evil threatening them personally. She is the last surviving member of the town's founding family and is exceptionally proud of that distinction—although it means little to anybody else. She is just a lonely old maid who has nothing to do with her time and has to make up activities to fill her days. A good example of this is the way she goes grocery-shopping practically every day and buys in very small quantities so that she will have to keep coming back and have at least one thing to do. She thinks she is so important as a person and as a customer that the store-owner Mr. Lewis should remember that she always buys a small quantity of tea on Tuesdays.

"Imagine your forgetting that I always buy my tea on Tuesday," Miss Strangeworth said gently. "A quarter pound of tea, please, Mr. Lewis."

There is no reason why she couldn't buy a full pound of tea once a month, but this gives her an excuse to keep coming back. Time weighs heavily on her hands. She has only discovered the pleasure of writing her poison-pen letters in the past year. They give her something to do, and she can tell herself that she is contributing to the welfare of the community. She cannot realize that she is a busybody and a troublemaker. Her letters are doing no good, only harm. Much of the evil she suspects in others is a projection of the evil inside herself. This is reminiscent of the biblical injunction:

1 Judge not, that ye be not judged.

2 For with what judgment ye judge, ye shall be judged: and with what measure ye mete, it shall be measured to you again.

3 And why beholdest thou the mote that is in thy brother's eye, but considerest not the beam that is in thine own eye?

4 Or how wilt thou say to thy brother, Let me pull out the mote out of thine eye; and, behold, a beam is in thine own eye?

5 Thou hypocrite, first cast out the beam out of thine own eye; and then shalt thou see clearly to cast out the mote out of thy brother's eye.

                                      Matthew 7:1-5 King James Version

So the alleged purpose of the letters is to guard the morals of her neighbors, while the real purpose is to give Miss Strangeworth something to do and to make her feel important. Why are the letters anonymous? Perhaps she senses somewhere deep in her unconscious that she is causing harm and that she could get in serious trouble for making what amount to false accusations. She can be more creative if her identity as the author is unknown. It is only by accident that her identity becomes known to one person, Don Crane, because she dropped his pink letter accidentally at the post office. But Don Crane probably will not tell anybody except his wife Helen who sent him that letter. He can't tell other people because then people will know who chopped up the old lady's rose bushes. Her secret is still safe for a while.

What is Miss Strangeworth's motivation in the story "The Possibility of Evil"?

Miss Strangeworth apparently does not understand how much trouble she is causing with her anonymous letters, nor does she seem to be aware of the real reason she is writing them. She tells herself she is doing her civic duty as the oldest person in the community and as the only surviving member of the family that founded the town. It would appear, from what we know of the people to whom she has been sending her letters, that she is motivated by envy, jealousy, and bitterness. She is a lonely old maid, and she feels embittered when she sees anyone who has another person to love. Her letters invariably damage human relationships. Perhaps, like Miss Emily Grierson in William Faulkner's story "A Rose for Emily," Miss Strangeworth has never in her entire life had anyone to love and to love her.

A good example of people victimized by Miss Strangeworth's unconscious jealousy is the high-school kids Linda Stewart and Dave Harris, who are very much in love. Miss Strangeworth has poisoned their innocent romance by writing an anonymous letter to Linda's parents hinting that Dave is carrying the relationship far beyond the usual hugging and kissing of kids their age.

Miss Strangeworth is probably jealous of Martha Harper because she has a husband. The letter to Mrs. Harper plants seeds of suspicion by hinting that everybody knows her husband is having an affair with another women in the town. Mrs. Harper is apparently a prime target. When Miss Strangeworth is writing her letters that day, we learn that she has written poison-pen letters to this woman before.

After thinking for a minute, she decided that she would like to write another letter, perhaps to go to Mrs. Harper, to follow up the ones she had already mailed. She selected a green sheet this time and wrote quickly: Have you found out yet what they were all laughing about after you left the bridge club on Thursday? Or is the wife really the last one to know?

Don and Helen Crane are not only happily married but have a six-months-old daughter they adore. Miss Strangeworth tries to increase their worries about their baby's development by sending a letter reading:

Didn't you ever see an idiot child before? Some people just shouldn't have children, should they?

This is intended to poison the Cranes' marital relations and prevent them from having any more children. 

Old Mrs. Foster has a nephew who is probably very important to her because he is apparently her only living relative. Miss Strangeworth sends her an anonymous letter reading:

You never know about doctors. Remember they're only human and need money like the rest of us. Suppose the knife slipped accidentally. Would Doctor Burns get his fee and a little extra from that nephew of yours?

This will make the old woman mistrustful of both her nephew and her doctor. Mrs. Foster is probably already sufficiently worried about undergoing a major operation at her age and may decide to cancel it. 

Mr. Lewis the grocer has a grandson who helps out in the store. 

Mr. Lewis would never have imagined for a minute that his grandson might be lifting petty cash from the store register if he had not had one of Miss Strangeworth’s letters.

We can feel sorry for Miss Strangeworth, as we do for Faulkner's Emily Grierson and for the lonely Miss Havisham in Charles Dickens' novel Great Expectations. Miss Strangeworth is obviously unaware of the jealousy and bitterness that so many other people in her town cause her just by being happy in having someone to care for. She keeps her feelings hidden from herself until the very end of the story.

She began to cry silently for the wickedness of the world when she read the words: Look out at what used to be your roses.

She is not really crying for the wickedness of the world but crying for all her years of unrequited longing for love. Her roses were a poor substitute for love, but they were the only substitute she had. 

What was Miss Strangeworth's motivation to write the poison pen letters in "The Possibility of Evil"?

We are never told exactly what motivates Miss Strangeworth to write her anonymous poison pen letters, but we are given several clues. In both of the quotes below, Miss Strangeworth dwells on the idea that the world is an evil place. She also repeats that she is the last Strangeworth left in the town. This suggests that the Strangeworths are the kind of people who have a history of being judgmental and seeing evil where none exists:

There were so many wicked people in the world and only one Strangeworth left in town. Besides, Miss Strangeworth liked writing her letters.

. . .

The town where she lived had to be kept clean and sweet, but people everywhere were lustful and evil and degraded, and needed to be watched; the world was so large, and there was only one Strangeworth left in it.

The quotes also give us some clues as to what might be going on beneath the surface of Miss Strangeworth. She is seeing evil lurking everywhere, and she believes she is the last of her family left to uphold morality by rooting out wickedness.

First, we learn that Miss Strangeworth likes writing the letters and that she perceives a divide between a town facade that is "clean and sweet" and the underlying (to her) reality that people are really "lustful and evil and degraded." It seems that Miss Strangeworth herself has felt forced to keep up too much of facade of sweetness and perhaps been trained to repress too many of her negative or aggressive emotions. They have welled up inside her as a poison, and she "likes" writing the letters because they help her express some of the anger and negativity she has been forced to hide. She is projecting her own evil onto others so she can continue to feel pure and good, and at same time, let some of her aggressions out.

What was Miss Strangeworth's motivation to write the poison pen letters in "The Possibility of Evil"?

Miss Strangeworth has been sending her poison-pen letters to people in her town for a long time. Does she just enjoy making trouble? Or is there a reason why she targets certain people? She is called Miss Strangeworth because she is obviously an old maid. This might seem to put her in the same category as Miss Havisham in Charles Dickens' Great Expectations and Emily Grierson in William Faulkner's "A Rose for Emily," both of whom are consumed with hatred. Miss Strangeworth may hate people who are happy because she has never been loved.

When she gets home she writes three of her letters. One of them goes to Don Crane. Miss Strangeworth had just been talking to his wife Helen, and she knows they are both worried about their six-month-old baby daughter's development. She may be motivated by jealousy of this young couple who love each other and now have a baby to love. So she writes:

Didn't you ever see an idiot child before? Some people just shouldn't have children, should they?

Her next letter is for Mrs. Harper. She may be jealous of her because she has a husband. She writes:

Have you found out yet what they were all laughing about after you left the bridge club on Thursday? Or is the wife really the last one to know?

She obviously would like to poison the long marital relationship between the couple by planting the suggestion that Mr. Harper is having an affair with another woman.

Miss Strangeworth's third and final letter is "to old Mrs. Foster, who was having an operation next month." She writes:

You never know about doctors. Remember they're only human and need money like the rest of us. Suppose the knife slipped accidentally. Would Doctor Burns get his fee and a little extra from that nephew of yours?

It could be surmised that Miss Strangeworth is jealous of Mrs. Burns because she has a lot of money and also because she has a nephew who loves her and looks after her.

Miss Strangeworth has created trouble for a couple of teenagers, Linda Stewart and Dave Harris. These two are going steady and are in love. This could easily make Miss Strangeworth sufficiently jealous to do what she did. She sent Linda's parents a letter suggesting that their fifteen-year-old daughter was having illicit relations with the Harris boy. She overhears the two youngsters talking when she gets to the post office to mail her three letters.

"I can't tell you, Dave," Linda was saying—so she was talking to the Harris boy, as Miss Strangeworth had supposed—"I just can't. It's just nasty."

"But why won't your father let me come around anymore? What on earth did I do?"

"I can't tell you. I just wouldn't tell you for anything. You've got to have a dirty, dirty mind for things like that." ....

It is a touch of irony that Dave Harris, who has no idea that Miss Strangeworth is the cause of his troubles with Linda's parents, tries to help the old lady out by hand-delivering her poison-pen letter to Don Crane and telling Don that Miss Strangeworth accidentally dropped it at the post office.