Prentis Battles, Jr. appeals from a judgment of the district court upholding a decision of the Secretary of Health and Human Services denying his claim for supplemental security income benefits. We reverse and remand.

In December 1991, Battles filed an application for benefits, alleging a disability due to back and "right side" problems. In a disability questionnaire, Battles, who was born in 1940, stated he had a seventh grade education, had not worked in fifteen years, and was homeless. He described a reclusive social life, indicating that he did not visit with people and that his relatives had nothing to do with him. In July 1992, Battles, who was represented by an attorney, appeared at a hearing before an administrative law judge (ALJ), claiming he could not work because of back pain, a "bad kidney," and breathing problems. In response to questions from his attorney, Battles stated that he could not "read or write too good," spent his days scavenging dumpsters for food and objects to sell, and spent nights sleeping in other people's cars.

The only evidence submitted in connection with the hearing was a February 1992 report of a consultative physician. Lumbar spine and chest x-rays were normal. The doctor diagnosed pain of unknown origin in the rib region and chronic obstructive lung disease.

The ALJ found that Battles' allegations of disabling pain were not credible and denied his claim for benefits.

Battles appealed the decision to the Appeals Council and submitted an additional medical report of an orthopedist, who found "no musculoskeletal condition to explain the patient's symptoms." The doctor, however, diagnosed chronic obstructive lung disease and advised a pulmonology evaluation. The Appeals Council upheld the ALJ's decision.

Battles then sought review in the district court, alleging that he was disabled by a combination of physical and mental impairments. He also filed a motion to remand under 42 U.S.C. Sec. 405(g) based on a report of Dr. William Wilkins, a psychologist who evaluated Battles in June 1993. Intelligence tests revealed that Battles had borderline intellectual functioning, with a full scale IQ score of 72, a verbal IQ of 80, and a performance IQ of 63. Psychological tests, coupled with social history, indicated that Battles had a "fairly well entrenched pattern of a schizotypal personality disorder," which was characterized by inappropriate behaviors, and suffered from "an almost lifelong history of significant alcohol abuse." He also suffered from severe dyslexia.1

The district court upheld the denial of benefits and denied the motion to remand.

On appeal Battles challenges the district court's denial of his motion to remand. He, however, suggests that the motion to remand probably would have been unnecessary had the ALJ fulfilled his duty to fully and fairly develop the record as to a mental impairment. We agree. The Secretary acknowledges that it is her " 'duty to develop the record fully and fairly, even if ... the claimant is represented by counsel.' " Boyd v. Sullivan, 960 F.2d 733, 736 (8th Cir.1992) (quoting Warner v. Heckler, 722 F.2d 428, 431 (8th Cir.1983)). This is so because an administrative hearing is not an adversarial proceeding. Henrie v. Dept. of Health & Human Serv., 13 F.3d 359, 361 (10th Cir.1993). "[T]he goals of the Secretary and the advocates should be the same: that deserving claimants who apply for benefits receive justice." Sears v. Bowen, 840 F.2d 394, 402 (7th Cir.1988). Moreover, "[a]n adequate hearing is indispensable because a reviewing court may consider only the Secretary's final decision [and] the evidence in the administrative transcript on which the decision was based." Higbee v. Sullivan, 975 F.2d 558, 562 (9th Cir.1992) (per curiam).

While the Secretary is correct that she is in under no duty to "go to inordinate lengths to develop a claimant's case[,]" Thompson v. Califano, 556 F.2d 616, 618 (1st Cir.1977), it is also true that she must "make an investigation that is not wholly inadequate under the circumstances." Miranda v. Secretary of Health, Educ. & Welfare, 514 F.2d 996, 998 (1st Cir.1975). "There is no bright line test for determining when the [Secretary] has ... failed to develop the record. The determination in each case must be made on a case by case basis." Lashley v. Secretary of Health & Human Serv., 708 F.2d 1048, 1052 (6th Cir.1983).

In the circumstances of this case, we believe that the ALJ failed to fully and fairly develop the record. Although length of a hearing is not dispositive, it is a consideration. Thompson v. Sullivan, 987 F.2d 1482, 1492 (10th Cir.1993). Here, the hearing "lasted a mere [ten] minutes, and was fully transcribed in approximately eleven pages." Lashley, 708 F.2d at 1052. The ALJ asked no questions and counsel's questions failed to shed light on Battles' mental capacity to work. "Superficial questioning of inarticulate claimants or claimants with limited education is likely to elicit responses which fail to portray accurately the extent of their limitations." Id. We believe that Battles' testimony that he was virtually illiterate, had not worked in fifteen years, ate out of garbage cans, slept in other people's cars, and had no relationships with other persons was "sufficient to raise an issue as to [his] mental and psychological capacity to engage in substantial gainful activity."2 Cannon v. Harris, 651 F.2d 513, 519 (7th Cir.1981). The Secretary's own rules provide that "mental illness is defined and characterized by maladaptive behavior." Social Security Ruling (SSR) 85-15. The rules recognize that "[i]ndividuals with mental disorders often adopt a highly restricted and/or inflexible lifestyle" and "emphasize the importance of thoroughness in evaluation on an individualized basis." Id. Indeed, the regulations provide a mandatory procedure to evaluate mental impairments, 20 C.F.R. Sec. 416.920a, and for examination by a psychiatrist or psychologist when there is "evidence which indicates the existence of a mental impairment." Id. at Sec. 416.903(e).3

Because we hold that the ALJ failed to fully and fairly develop the record,4 we need not address the question whether the district court abused its discretion in denying Battles' motion to remand. We merely observe in passing that should that question be addressed there certainly is authority for denial of relief on the motion to remand. See Smith v. Shalala, 987 F.2d 1371, 1375 (8th Cir.1993).

Accordingly, we reverse the judgment of the district court and remand this case with instructions to remand to the Secretary for further proceedings.