Inference questions tend to be among the most challenging types of Reading Comprehension questions on the SAT. Instead of testing your understanding of what is in the text, inference questions test your understanding of what isn’t in the text.

Correct answers to these questions are, however, directly implied by what the author states explicitly. If you think logically and carefully, there is no reason for this type of question to be prohibitively difficult.

Imagine that you read an ad that says, “Unlike our competitor’s yogurt, ours is organic.” The implied meaning is obviously that “our competitor’s yogurt is not organic.” This little mental “flip” is an essential skill for SAT inference questions.

For example, consider this extremely brief passage: All terrichnoderms are classified by biologists as members of the phylum Aeridae. As opposed to members of the phylum Aeridae, phractopods do not have tails that can be used for balance, stability, and navigation.

That’s all the information you get. Below is an example of a question that can be answered with only the two facts above, and no outside information.

Which of the following can be inferred from the passage?

A. Because geckos have tails that can be used for balance, stability, and navigation, they are members of the phylum Aeridae
B. Because phractopods do not have tails, their balance and navigation abilities are less developed than those of animals in the phylum Aeridae
C. Terrichnoderms were not always classified by biologists as members of the phylum Aeridae
D. Terrichnoderms have tails that can be employed for stabilizing and balancing

Whoa, that’s kind of hard! Do not make wild guesses. Instead, go back and organize the information in this passage. You can use “T” for terrichnoderms, “A” for Aeridae, and “P” for phractopods.

You are first told “All T are A.” Easy.

Then, you are told, “As opposed to A, P do not have tails that can be used for balance, stability, and navigation.” So, when the passage says, “As opposed to A, P do NOT have these kinds of tails,” it means that members of A DO have these kinds of tails.

The passage is deliberately feeding you a particular conclusion - a conclusion that must be true based on the information in the passage. Next, go through the answers one by one:

A. You do know that “A” have tails that can be used for balance, stability, and navigation, but you do N O T know that anything that has such a tail is therefore “A”. (For instance, all mammals have bones, but not everything with bones is a mammal). Incorrect.
B. You don’t know this! All you are told is that “phractopods do not have tails that can be used for balance, stability, and navigation.” Maybe they DO have tails (the tails just can’t be used for balance, stability, and navigation). And, of course, they might have other, perfectly good body parts (other than tails) that they can use for balance and navigation. You can’t infer things you just weren’t told. Incorrect.
C. You have absolutely no information about the history of biologists’ classifications of anything. Perhaps you could argue that many thousands of years ago, there were no biologists, and thus biologists could not have classified T as A, but that idea is just not based on the passage. Incorrect.
D. You wrote at the bottom of your diagram that, “A have tails that can be used for balance, stability, and navigation.” Answer choice D is about T, though, not A. But wait a minute! Your diagram says, “All T are A”! If all T are A, and A have these special tails, then T have these special tails! (This is like the transitive property in math!) This answer is a direct match with the information in the passage. Correct.

FYI: There’s no such thing as a terrichnoderm, a phractopod, or a phylum called Aeridae. It is all made up in order to show you that you can succeed simply by organizing the information you were given. Just to be clear, the SAT does not make up information - the makers of the exam pull the information from published sources. Here, I was just making a point.

Basics

An inference sticks pretty closely to the facts. To infer for SAT purposes is to use only the information in the passage in order to draw a conclusion that cannot be wrong.

When answering an inference question, the following are indicators of a wrong answer:

1. Answers that are probably true (but not definitely)
2. Answers that require additional assumptions

That is, drawing an inference is NOT the same as making an assumption about something that a normal person would assume is probably true. Making assumptions will get you a wrong answer! Picking something that is probably true will also get you a wrong answer!

So, what kind of conclusion could you possibly draw from an SAT passage, using only the information in the passage and not assuming anything? A really boring, trivial, not very insightful one. Seriously.

For instance, if a teacher tells you “Joey failed the test.” What can you infer? That Joey didn’t study? No, maybe he did study and still failed. That the test was hard? Not necessarily. The only thing you can infer is that Joey did not pass the test.

That’s kind of stupid, isn’t it? But it certainly isn’t wrong. Try to argue with “Joey did not pass the test.” You can’t. That’s why it’s an inference.

By the way, not every inference question uses the word infer. Many questions use words such as suggest or imply. For purposes of the SAT, treat all these questions the same way: pick an answer choice that has to be true based on the relevant information from the passage.

Example 1:
          In the early 1940s, women’s participation in the U.S. labor market changed dramatically as a result of the labor shortages resulting from the drafting of men to fight in World War II. While persistent and institutionalized discrimination had discouraged women from paid work in the Depression era, the wartime government used patriotic propaganda to encourage women to work in defense industries. While women’s employment was still viewed as an extraordinary measure for extraordinary times - and the woman worker as merely filling in for “some soldier” to whom the job properly belonged - gender barriers were lowered somewhat during this period, and pay began to equalize. Despite these moves towards women’s participation in the workforce, however, shifting forces in the postwar labor market meant that fewer American women worked outside the home in 1952 than in 1942.

1. Which of the following can be inferred regarding women’s employment during the period discussed in the passage?
A. Discrimination against women in the workplace increased between 1942 and 1952
B. Women’s job qualifications decreased during the period 1942-1952
C. The end of World War II caused many men to come home and take back jobs they had once held
D. More women worked outside the home in 1942 than ten years later
‍

Solution:
What do you know from the passage? Not much: fewer women worked in 1952 than in 1942, and the cause of this is “shifting forces in the postwar labor market.” You need to pick an answer choice that MUST be true, based on only those facts. You should examine the choices.

A. We have no way to know this. We are told that employment decreased during that period, but you don’t know why. INCORRECT.
B. Again, we have no way to know. We’re told that employment decreased during that period, but not why. INCORRECT.
C. This is a trap. We’re told that the drop in employment is due to “shifting forces in the postwar labor market,” and the idea of men coming back from war and taking back jobs is certainly consistent with that, but consistent isn’t enough. The answer choice may be true, but it’s not the answer to the question because we cannot infer it from the information in the passage. INCORRECT.
D. If fewer women worked in 1952 than in 1942, then MORE women worked in 1942 than in 1952. That’s a pretty trivial observation. But it MUST be true, based only on the information in the passage. That’s why it’s the answer. CORRECT.

Once you get the hang of drawing inferences, you can do it very quickly and easily. For instance, what can you infer from this sentence? In 2008, Ecuador became the first nation in the world to pass a Constitution codifying the rights of nature.

The inference is essentially this: Prior to 2008, no nation had passed a Constitution codifying the rights of nature. You could even infer something like this: As of 2007, the United States Constitution did not codify the rights of nature. That’s kind of random, but definitely true based only on the information presented.

Here’s another Example: Because of monumental shifts in the social behavior the researcher studied in the 1970s, the researcher’s methodology has proved to be of more lasting value than her results.

It might be helpful to paraphrase the original information first. Maybe something like, Since a lot has changed since the ‘70s, the researchers methodology is still valuable, but the results are less valuable. The inference is something like, “The results are out of date.”

Important: Make sure that you pay close attention to negatively phrased answer choices or answers that contain double negatives (e.g., not impossible = possible). Unless you carefully work out what this type of wording actually means, it can very easy confused you.

This tip is important because one of the easiest ways to create a valid inference is to rewrite the original statement from a different angle. For example, if a passage states that a star is much older than the Earth, a valid inference is that the star is not younger than the Earth.

Lastly, as with all reading questions, it is vital to predict an answer before you look at the answer options to avoid getting confused. This particularly important for inference questions.

Follow these steps to follow when tackling an inference question:

1. Find the right part of the passage and read it, underlining clue words that relate to the question
2. Predict possible answers by making logical inferences
3. Eliminate wrong answers, looking out for ones that go too far, are too specific, use outside knowledge, or mix up information
4. Pick the correct answer! It will be very close to what the passage says

Example 2:
         In a command economy, the government decides what goods and services will be produced and what prices will be charged for them. The government decides what methods of production will be used and how much workers will be paid. Many necessities like healthcare and education are provided for free. Currently, Cuba and North Korea have command economies.

The passage most directly suggests that most countries around the world
A. do not require citizens to pay for their healthcare costs.
B. have a poor opinion of the economies of Cuba and North Korea.
C. do not determine workers’ wages with government policy.
D. are free to decide which type of economy to implement

Solution: 
Since the passage mentions only two countries that have “command economies,” it is reasonable to deduce that “most countries” do not have command economies. This would mean that they don’t have the characteristics of a command economy (including deciding how much workers are paid). C is the correct answer. 

Answer D sounds possible, maybe even realistic. But the passage does not suggest anything about countries deciding on a type of economy, do this choice does not answer the question.

Example 3: The following passage is adapted from Jane Austen, Northanger Abbey, originally published in 1817.
           
                No one who had ever seen Catherine Morland in her infancy would have supposed hr born to be a heroine. Her situation in life, the character of her father and mother, her own person and disposition, were all equally against her. Her father was a clergyman, without being neglected, or poor, and a very respectable man, though his name was Richard, and he had never been handsome. He had a considerable independence besides two good livings - and he was not in the least addicted to locking up his daughters. Her mother was a woman of useful plain sense, with a good temper, and, what is more remarkable, with a good constitution. She had three sons before Catherine was born; and instead of dying in bringing the latter into the world, as anybody might expect, she still lived on - lived to have six children more - to see them growing up around her, and to enjoy excellent health herself. A family of ten children will be always called a fine family, where there are heads and arms and legs enough for the number; but the Morlands had little other right to the word, for they were in general very plain, and Catherine, for many years of her life, as plain as any. She had a thin awkward figure, a sallow skin without colour, dark lank hair, and strong features - so much for her person; and not less unpropitious for heroism seemed her mind. She was fond of all boy’s plays, and greatly preferred cricket not merely to dolls, but to the more heroic enjoyments of infancy, nursing a dormouse, feeding a canary-bird, or watering a rose-bush. Indeed she had no taste for a garden; and if she gathered flowers at all, it was chiefly for the pleasure of mischief - at least so it was conjectured from her always preferring those which she was forbidden to take. Such were her propensities-her abilities were quite as extraordinary She never could learn or understand anything before she was taught; and sometimes not even then, for she was often inattentive, and occasionally stupid. Her mother was three months in teaching her only to repeat the “Beggar’s Petition”; and after all, her next sister, Sally, could say it better than she did. Not that Catherine was always stupid-by no means; she learnt the fable of “The Hare and Many Friends” as quickly as any girl in England. Her mother wished her to learn music; and Catherine was sure she should like it, for she was very fond of tinkling the keys of the old forlorn spinner; so, at eight years old she began. She learnt a year, and could not bear it; and Mrs. Morland, who did not insist on her daughters being accomplished in spite of incapacity or distaste, allowed her to leave off. The day which dismissed the music-master was one of the happiest of Catherine’s life. Her taste for drawing was not superior; though whenever she could obtain the outside of a letter from her mother or seize upon any other odd piece of paper, she did what she could in that way, by drawing houses and trees, hens and chickens, all very much like one another. Writing and accounts she was taught by her father; French by her mother: her proficiency in either was not remarkable, and she shirked her lessons in both whenever she could. What a strange, unaccountable character!-for with all these symptoms of profligacy at ten years old, she had neither a bad heart nor a bad temper, was seldom stubborn, scarcely ever quarrelsome, and very kind to the little ones, with few interruptions of tyranny; she was moreover noisy and wild, hated confinement and cleanliness, and loved nothing so well in the world as rolling down the green slope at the back of the house.

Questions 
1. An unstated assumption in the narrator’s description of Catherine is that a heroine is typically
A. bold and daring
B. brilliant and beautiful
C. wild and rebellious
D. independent and carefree

2. The narrator suggests that Catherine’s mother responded to her daughter’s imperfections with
‍A. frequent irritation
B. general indifference
C. easy indulgence
D. utter perplexity

3. The narrator suggests implies that Catherine was strongly motivated to do things that
‍A. were unusually difficult
B. were taught by her parents
C. were not permitted
D. her siblings could not do

4. The narrator’s references to a dormouse and rose bush suggests that Catherine
‍A. could behave in a cruel manner
B. preferred to play alone than with other children
C. rejected a range of conventionally feminine activities
D. recognized her exceptional behavior

‍Solutions: 
1. Virtually the entire passage involves the narrator describing the various ways in which Catherine is unsuited to being a heroine, so you can infer that a heroine should be all of the things that Catherine is not. The correct answer is B. The other answers refer to attributes that could be associated with Catherine.

2. The passage states that Mrs. Morland is generally good-natured. C is the correct answer because it is the only positive option. To get there, start by plugging in the line references and looking for information that suggests how Catherine’s mother responded to her antics.

3. If you have enough of a sense of the passage to understand that Catherine is somewhat naughty, you can make a reasonable assumption that the correct answer is C. If not, plug in the line references and check which support that idea.

4.Start by considering the full sentence in which the references appear. The point of the sentence is that Catherine preferred boys’ games, which is simply another way of saying that she “rejected conventionally feminine activities.” C is the correct answer.